Nginx conf for laravel不起作用

I'm using laravel in my centos 6.7 and webuzo. I can run my script on apache before, but when i mirgate it to nginx, it won't run. I think the problem is, i can't use this nginx conf :

server {
listen 80;
server_name myapp.localhost.com;
root /srv/smile/public;

index index.html index.htm index.php;

charset utf-8;

location / {
    try_files $uri $uri/ /index.php?$query_string;
}

location = /favicon.ico { access_log off; log_not_found off; }
location = /robots.txt  { access_log off; log_not_found off; }

access_log off;
error_log  /var/log/nginx/myapp-error.log error;

sendfile off;

client_max_body_size 100m;

location ~ \.php$ {
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass unix:/var/run/php5-fpm.sock;
    fastcgi_index index.php;
    include fastcgi_params;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_intercept_errors off;
    fastcgi_buffer_size 16k;
    fastcgi_buffers 4 16k;
}

location ~ /\.ht {
    deny all;
}
}

Everytime i put this config in nginx.conf, nginx service won't restart. What could be wrong with this conf ?