HELP Integration API!

I will integration ERPNext with other application, and i will post data SALES ORDER Doctype with API,
what is the standard format json SALES ORDER doctype?

check this .
https://frappe.io/docs/user/en/guides/integration/rest_api

i can’t find json format for sales order.

you should read this and make your json according this format.
https://frappe.io/docs/user/en/guides/integration/rest_api/manipulating_documents