您已经在pub/wp安装了WordPress，但是您的Nginx配置只引用了/wp/。请修改您的Nginx配置以引用/pub/wp/，或者将WordPress移到根目录（例如/wp/）。
https://fishpig.co.uk/magento/wordpress-integration/nginx/

upstream fastcgi_backend {
  server  127.0.0.1:9000;
}

server {
  listen 80;

  # Magento 2 base URL
  server_name m2.latest.composer.fp.com;

  # Magento 2 root directory
  set $MAGE_ROOT /home/magento2/html;

  set $MAGE_DEBUG_SHOW_ARGS 1;

  include /home/magento2/html/nginx.conf.sample;

  # WordPress is installed in pub/wp
  location /wp/ {
    index index.html index.php;
    try_files $uri $uri/ /wp/index.php?q=$uri&args;

    location ~ \.php$ {
      fastcgi_pass   127.0.0.1:9000;
      fastcgi_index  /wp/index.php;
      include        fastcgi.conf;
    }
  }
}

我的magento项目安装在docker上。我的WP站点安装在pub/wp/。安装时我使用了此文档https://fishpig.co.uk/magento/wordpress-integration/docs/
我也面临着同样的问题。
我通过将fastcgi_pass的值更改为我的docker容器（fastcgi_backend）中使用的值来解决这个问题：

location /wp/ {
index index.html index.php;
try_files $uri $uri/ /wp/index.php$is_args$args;
location ~ \.php$ {
    fastcgi_pass   fastcgi_backend;
    fastcgi_index  /wp/index.php;
    include        fastcgi.conf;
}

之后，您需要更改wp_options表中的站点URL和主页值