归根结底，需要通过删除搜索重写规则来禁用搜索slug。我创建了一个插件（也在wp.org repo上）：https://github.com/GaryJones/disable-search-slug

以下是主文件：

<?php
/**
 * Disable Search Slug Plugin
 *
 * @package   Gamajo\\DisableSearchSlug
 * @author    Gary Jones
 * @license   GPL-2.0+
 * @copyright 2016 Gamajo Tech
 *
 * @wordpress-plugin
 * Plugin Name:       Disable Search Slug
 * Description:       Stops <code>/search/...</code> URLs from working, resulting in a WordPress 404 page not found.
 * Version:           1.0.1
 * Author:            Gary Jones
 * Text Domain:       disable-search-slug
 * License:           GPL-2.0+
 * License URI:       http://www.gnu.org/licenses/gpl-2.0.txt
 * GitHub Plugin URI: https://github.com/GaryJones/disable-search-slug
 * GitHub Branch:     master
 */

// Wipe out rules for search permalink structure on every page load, in case the
// rules are flushed by WP core, another plugin, a user visiting Settings -> Permalinks.
add_action( \'init\', function() {
    add_filter( \'search_rewrite_rules\', \'__return_empty_array\' );
} );

register_activation_hook( __FILE__ , function() {
    // Wipe out the rules for search permalink structure, on plugin activation.
    add_filter( \'search_rewrite_rules\', \'__return_empty_array\' );
    flush_rewrite_rules();
} );

register_deactivation_hook( __FILE__ , function() {
    // Undo the change in rules to search rules, and flush the rules, on plugin deactivation.
    remove_filter( \'search_rewrite_rules\', \'__return_empty_array\' );
    flush_rewrite_rules();
} );