I have a strange use.
I used aria2 to make a download machine, and used nginx to index the download directory. autoindex is turned on. However, if I accidentally download it using aria2 The homepage of a website or downloaded is saved as index.html. When I access the download directory, index.html will be opened directly. I hope it will never do this automatically, even if there is index.html Don’t open it either. I first removed index and found that it didn’t work at all. The place where index.html was automatically parsed before was still parsed. So I tried index ;With such a parameter, if nginx cannot be started, an error will be reported.
Now I hope that only when accessing the root path /, index.html will be automatically selected for display. , and when accessing /down and /res, index.html will be ignored and the file list in the directory will be displayed directly.
The following is my corresponding virtual Host settings:

# You may add here your
# server {
#       ...
# }
# statements for each of your virtual hosts to this file

##
# You should look at the following URL's in order to grasp a solid understanding
# of Nginx configuration files in order to fully unleash the power of Nginx.
# http://wiki.nginx.org/Pitfalls
# http://wiki.nginx.org/QuickStart
# http://wiki.nginx.org/Configuration
#
# Generally, you will want to move this file somewhere, and start with a clean
# file but keep this around for reference. Or just disable in sites-enabled.
#
# Please see /usr/share/doc/nginx-doc/examples/ for more detailed examples.
##

server {
        #listen   80; ## listen for ipv4; this line is default and implied
        #listen   [::]:80 default_server ipv6only=on; ## listen for ipv6

        root /nginx;

        # Make site accessible from http://localhost/
        server_name localhost;
        # Exclude down&res directory
        location /down {
                try_files $uri $uri/ =404;
                alias /mnt/UDisk/;
                allow all;
                autoindex on;
                autoindex_format json;
        }
        location /res {
                try_files $uri $uri/ =404;
                alias /mnt/ResDisk/;
                allow all;
                autoindex on;
                autoindex_format json;
        }
        location = / {
                #index index.html;
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ / =404;
                # Uncomment to enable naxsi on this location
                # include /etc/nginx/naxsi.rules
        }
        #location /RequestDenied {
        #       proxy_pass http://127.0.0.1:8080;
        #}

        #error_page 404 /404.html;

        # redirect server error pages to the static page /50x.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$ {
        #       fastcgi_split_path_info ^(.+\.php)(/.+)$;
        #       # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
        #
        #       # With php5-cgi alone:
        #       fastcgi_pass 127.0.0.1:9000;
        #       # With php5-fpm:
                fastcgi_pass unix:/var/run/php5-fpm.sock;
                fastcgi_index index.php;
                include fastcgi_params;
        }

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #       deny all;
        #}
}


# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
#       listen 8000;
#       listen somename:8080;
#       server_name somename alias another.alias;
#       root html;
#       index index.html index.htm;
#
#       location / {
#               try_files $uri $uri/ =404;
#       }
#}


# HTTPS server
#
#server {
#       listen 443;
#       server_name localhost;
#
#       root html;
#       index index.html index.htm;
#
#       ssl on;
#       ssl_certificate cert.pem;
#       ssl_certificate_key cert.key;
#
#       ssl_session_timeout 5m;
#
#       ssl_protocols SSLv3 TLSv1;
#       ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv3:+EXP;
#       ssl_prefer_server_ciphers on;
#
#       location / {
#               try_files $uri $uri/ =404;
#       }
#}