我会在插件文件中使用init hook来注册自定义函数

add_action( \'init\', \'custom_proccess_form\' );

function custom_proccess_form() {

    $wp_error = true;   // report errors or not
    $nonce = $_POST[\'_wpnonce\'];

    if( isset($_POST[\'insert_post\']) && wp_verify_nonce($nonce, \'my-nonce-name\') ) {

        $post = array(
            \'post_title\' => $_POST[\'new_post_title\'],
            \'post_content\' => $_POST[\'new_post_content\'],
            );

        // form actions
        $post_id = wp_insert_post( $post, $wp_error );

        // now you can use $post_id within add_post_meta or update_post_meta

        // redirect at the end to some url
        wp_redirect(\'/?success=true\');
    }
}

<form method="POST">
    <?php wp_nonce_field(\'my-nonce-name\'); ?>
    <input type="text" name="new_post_title">
    <textarea name="new_post_content"></textarea>
    <input type="hidden" name="insert_post" value="1">
    <button type="submit">Submit!</button>
</form>