Some questions about building a LEMP environment

I set up a LEMP environment under ubuntu 12.04 version. I followed the online tutorial to configure step by step. I found that accessing index.php kept reporting a 404 NOT FOUND error (if the file name is changed back to index.html, it can be accessed normally). How to solve the problem? ?
cgi.fix_pathinfo=0 and listen = /var/run/php5-fpm.sock have been set in the PHP related configuration file
nginx configuration information is as follows:

<code>server {
    listen       80;


    root   /vagrant/www/;
    index  index.php index.html index.htm;

    server_name localhost;

    error_page 404 /404.html;
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/www;
    }

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    location ~ \.php$ {
         try_files $uri =404;
         fastcgi_split_path_info ^(.+\.php)(/.+)$;
         fastcgi_pass unix:/var/run/php5-fpm.sock;
         fastcgi_index index.php;
         fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
         include  fastcgi_params;
    }
}</code>