Abstract: This paper analyzed the application requirements in various fields of low orbit internet constellation communication, studied the space network transmission and network scene characteristics of low orbit internet constellation, and investigated the existing communication protocols such as terrestrial telecommunications network protocols, terrestrial internet protocols, and space network protocols. Based on the TCP/IP model, this paper introduced the concept of "protocol modules", and designed a communication protocol system for low orbit internet constellations. Moreover, a communication protocol standard system was preliminarily constructed to provide reference for the construction and operation of low orbit internet constellations of the country.