您可以使用wp_insert_post 用户创建/保存“普通”帖子，然后查找其自定义帖子并复制到所需的任何字段时的操作：

function wpse_203349_copy_post_meta( $post_ID, $post, $update ) {
    if ( $post->post_type !== \'post\' )
        return;

    $users_custom_posts = get_posts(
        array(
            \'posts_per_page\' => 1,
            \'post_author\' => $post->post_author,
            \'post_type\' => \'custom_post_type\',
        )
    );

    if ( ! $users_custom_posts )
        return; // This author doesn\'t currently have any custom posts

    $fields = get_post_custom( $users_custom_posts[0]->ID );

    foreach ( $fields as $field => $value ) {
        if ( $field[0] !== \'_\' && ( empty( $value[0] ) || ! is_array( $value[0] ) ) ) // Ignore "private" fields (prefixed with an underscore or serialized data)
            add_post_meta( $post_ID, $field, empty( $value[0] ) ? \'\' : $value[0], true /* Unique */ ); // If the field already exists, it won\'t be overwritten, unlike update_post_meta()
    }
}

add_action( \'wp_insert_post\', \'wpse_203349_copy_post_meta\', 10, 3 );