In order to adapt to the transmission mode with digital sampling value,to solve the problems that the phase detection is not easy to be implemented by the lack of professional phase detection equipment for intelligent substation,this paper proposes a distributed phase detection system for intelligent substation which based on WIFI wireless transmission network.Introduces the system architecture and implementation scheme of the phase detection system,researches the key technology of distributed digital phase detection,such as adaptive transmission of sampling value,area synchronization with wireless and phase measurement.The experiments show that the phase acquisition precision of the system based on wireless communication is high,the result of the phase detection is accurate and the operation is convenient,it can meet the functional requirements of the whole substation phase detection in the intelligent substation.