How to make LAN program with PHP ?

You'll have to be a little more specific.

Yep, some more details would be appreciated.

You can however setup a web server, and assign it a static IP. You can then either connect to it directly with the IP or setup a DNS and use a domain. This means that you can run your PHP scripts from within your LAN as you would if you placed it on a public server as a website.

I agree to what AHarrisGsy is saying. additional to that, in your local server, you can set the config for static IP address on your localserver (wampp, xampp or IIS). then on your URL, you can access it by replacing the localhost with the post configured static IP address.

e.g.
http://localhost/mysite

could be
http://192.131.0.11/mysite