Abstract: In Mobile field information intelligent service system, the long-range wireless network communication protocol is very important to ensure the validity of field information. As a result of the complex and diverse field information, a universal network protocol can not be designed. The design must be based on the concrete demand in actual application. So this paper presents a wireless network transmission protocol based on TCP/IP which makes the rules of information transmission between host information service system and PDA. Using the protocol, mobile field information intelligent service system realizes the seamless connection between remote server and mobile terminals, and the remote host server can manage mobile terminals effectively, which lays the foundation for monitoring the soil moisture, temperature and other data.