您应该使用transition_post_status 提交帖子后过滤内容。

在中尝试以下代码functions.php 在您的主题中：

add_action( \'transition_post_status\', \'_new_post\', 10, 3 );

function _new_post( $new_status, $old_status, $post ) {
    if ( \'publish\' !== $new_status or \'publish\' === $old_status ) {
        return;
    }

    if ( \'post\' !== $post->post_type ) {
        return;
    } // restrict the filter to a specific post type

    $plain_content = strip_tags( $post->post_content );
    $new_post      = array(
        \'ID\'           => $post->ID,
        \'post_content\' => $plain_content,
    );

    wp_update_post( $new_post );
}