Wordpress永久链接错误404

I am doing a wordpress page on digitalocean. I have a problem when I set permantlinks in my dashboard. The problem is, the server switch links, but sending to a 404 page.

http://5.101.99.123/ there is my server.

1. I Delete old .htaccess
2. Module rewrite already enable (sudo a2enmod rewrite)
3. I tried 777 on .htaccess
4. The server is working on ubuntu 14.04

Thanks in advance.