好的，这里有一个尝试，但是我不知道你的类别分类法的确切结构，所以它可能需要一些轻微的调整。我已经更新了表单的HTML，以便它使用用户选择的值，然后有一块PHP代码运行自定义WP_Query 要显示相关帖子（您可以编辑这些帖子以显示您喜欢的方式，目前它只返回无序的帖子列表）

HTML表单

<!-- THE HTML FOR THE FORM -->
<form action="" method="post">
    <div class="customsearchul">
    <div id="searchArea">
    <ul>
        <?php // Get the values from $_POST for area
            if($_POST[\'area\']) { $a=$_POST[\'area\'];} else { $a=\'\';} ?>
        <li><h4>Area:</h4></li>
        <li>All of London<input type="radio" name="area" value="london" <?php if ($a == \'london\' || ! isset($_POST[\'area\']) ) { echo \'checked\'; } ?> /></li>
        <li>North<input type="radio" name="area" value="north" <?php if ($a == \'north\' ) { echo \'checked\'; } ?> /> </li>
        <li>East<input type="radio" name="area" value="east" <?php if ($a == \'east\') { echo \'checked\'; } ?> /> </li>   
        <li>South<input type="radio" name="area" value="south" <?php if ($a == \'south\') { echo \'checked\'; } ?> /></li>
        <li>West<input type="radio" name="area" value="west" <?php if ($a == \'west\') { echo \'checked\'; } ?> /></li>
        <li>Central<input type="radio" name="area" value="central" <?php if ($a == \'central\') { echo \'checked\'; } ?> /></li>
    </ul>  
    </div>
</div>

<div class="customsearchul">
    <div id="searchMusic">
        <ul>
        <?php // Get the values from $_POST for music
            if($_POST[\'music\']) { $m=$_POST[\'music\'];} else { $m[]=\'\';} ?>                      
            <li><h4>Music:</h4></li>
            <li>House<input type="checkbox" name="music[]" value="house" <?php if (in_array(\'house\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Techno<input type="checkbox" name="music[]" value="techno" <?php if (in_array(\'techno\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Trance<input type="checkbox" name="music[]" value="trance" <?php if (in_array(\'trance\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Electronica<input type="checkbox" name="music[]" value="electronica" <?php if (in_array(\'electronica\', $m)) { echo \'checked\'; } ?> /></li>  
            <li>Drum and Bass<input type="checkbox" name="music[]" value="drum-and-bass" <?php if (in_array(\'drum-and-bass\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Garage<input type="checkbox" name="music[]" value="garage" <?php if (in_array(\'garage\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Dubstep<input type="checkbox" name="music[]" value="dubstep" <?php if (in_array(\'dubstep\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Trap<input type="checkbox" name="music[]" value="trap" <?php if (in_array(\'trap\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Hip-Hop<input type="checkbox" id="music" name="music[]" value="hiphop" <?php if (in_array(\'hiphop\', $m)) { echo \'checked\'; } ?> /></li>
            <li>R\'n\'B<input type="checkbox" name="music[]" value="rnb" <?php if (in_array(\'rnb\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Rock<input type="checkbox" name="music[]" value="rock" <?php if (in_array(\'rock\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Indie<input type="checkbox" name="music[]" value="indie" <?php if (in_array(\'indie\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Reggae<input type="checkbox" name="music[]" value="reggae" <?php if (in_array(\'reggae\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Retro 80\'s/90\'s<input type="checkbox" name="music[]" value="retro" <?php if (in_array(\'retro\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Party Bangers<input type="checkbox" name="music[]" value="party-bangers" <?php if (in_array(\'party-bangers\', $m)) { echo \'checked\'; } ?> /></li>
            <li>Chart Hits<input type="checkbox" name="music[]" value="chart-hits" <?php if (in_array(\'chart-hits\', $m)) { echo \'checked\'; } ?> /></li>
        </ul>  
    </div>
</div>

<div class="customsearchul">
    <div id="searchType">
        <ul>
        <?php // Get the values from $_POST for music
            if($_POST[\'occasion\']) { $o=$_POST[\'occasion\'];} else { $o[]=\'\';} ?>                                 
            <li><h4>Search Type:</h4></li>
            <!--<li>Everything<input type="checkbox" name="occasion[]" value="debauchery" /></li> -->
            <li>Nightclubs<input type="checkbox" name="occasion[]" id="nightclub" value="nightclub" <?php if (in_array(\'nightclub\', $o)) { echo \'checked\'; } ?> /></li>
            <li>Events &amp; Tickets<input type="checkbox" name="occasion[]" value="club-guide" <?php if (in_array(\'club-guide\', $o)) { echo \'checked\'; } ?> /> </li>   
            <li>Live Venues<input type="checkbox" name="occasion[]" value="festivals" <?php if (in_array(\'festivals\', $o)) { echo \'checked\'; } ?> /></li>
            <li>Artist Interviews<input type="checkbox" name="occasion[]" value="artist" <?php if (in_array(\'artist\', $o)) { echo \'checked\'; } ?> /></li>
        </ul>
    </div>
</div>
<input class="searchbutton" type="submit" value="Search" id="performsearch"/>
</form> 

<?php
    // Get the values from $_POST
    $a = ($_POST[\'area\']);
    $m = ($_POST[\'music\']);
    $o = ($_POST[\'occasion\']);

    // Change the ID of the area category
    $a_tmp = get_category_by_slug( $a );
    $a_catID[] = $a_tmp->term_id;

    // Get the ID of each music category
    // Do some conditional checks to make sure
    // that we\'re correctly indexing an array
    // and that output is an array for the later
    // use with array_merge()
    if ( is_array($m) ) {
        // If we already have an array it means
        // multiple checkboxes have been selected
        foreach( $m as $m_cat ){
            $m_tmp = get_category_by_slug( $m_cat );
            $m_catIDs[] = $m_tmp->term_id;
        }
    } else {
        // If we don\'t have an array then
        // only one checkbox has been 
        // selected
        $m_tmp = get_category_by_slug( $m );
        $m_catIDs[] = $m_tmp->term_id;
    }

    // Get the ID of each occasion category
    // with the checking as described above
    if ( is_array($o) ) {
        foreach( $o as $o_cat ){
            $o_tmp = get_category_by_slug( $o_cat );
            $o_catIDs[] = $o_tmp->term_id;
        }
    } else {
        $o_tmp = get_category_by_slug( $o );
        $o_catIDs[] = $o_tmp->term_id;
    }

    // Concatenate the arrays
    $cat_IDs = array_merge($a_catID,$m_catIDs,$o_catIDs);

    // Build the WP_Query arguments
    $query_args =
        array (
            \'post_type\' => \'post\',
            \'post_status\' => \'publish\',
            //\'category__and\' => $cat_IDs
            \'tax_query\' => array(
                    array(
                        \'taxonomy\' => \'category\',
                        \'field\' => \'term_id\',
                        \'operator\' => \'AND\',
                        \'terms\' => $cat_IDs
                    ),
                )

        );//end $query_args;

    $the_query = new WP_Query($query_args);

    // The Loop to echo posts
    if ( $the_query->have_posts() ) {
            // if we have posts, echo opening <ul>
            echo \'<ul>\';

        while ( $the_query->have_posts() ) {
            // while we have posts, echo the title in an <li>
            $the_query->the_post();
            echo \'<li>\' . get_the_title() . \'</li>\';
        }
            // echo the closing <ul>
            echo \'</ul>\';
    } else {
        // no posts found
        echo \'Nothing found.\';
    } wp_reset_postdata();      /* Restore original Post Data */

?>

您需要仔细检查分类设置，并确保调用get_category_by_slug 正在传递类别的slug可能会更改从循环输出的HTML，因此它不仅仅是<ul>