你真的不需要使用&new WP_Query 只是new WP_Query.

以下代码将解决您的问题。

add_filter( \'posts_search\', \'q166788_search_modify\', 10, 2 );

function q166788_search_modify( $sql, $query ){
    // Only if our variable is true we do the black magic
    if ( ! isset( $query->query_vars[\'search_conditional_toggle\'] ) || $query->query_vars[\'search_conditional_toggle\'] !== true ){
        return $sql;
    }

    return preg_replace(\'/AND/\', \'OR\', $sql, 1 );
}

// The actual search
    $s = \'bord\';

    $args = array (
        \'author\' => \'1,2,3,4,5\',
        \'s\' => $s,
        \'search_conditional_toggle\' => true, // Make the black magic happen
        \'posts_per_page\' => -1
    );

    $allsearch = new WP_Query( $args );

    var_dump( $allsearch );