The invention discloses a wireless sensor network communication protocol method of an automatic cathodic protection data collection system and relates to the technical field of digital information transmission and pipe systems. The wireless sensor network communication protocol method adopts a three-layer protocol structure which comprises a physical radio frequency layer, a network layer and an application layer from bottom to top, wherein the physical radio frequency layer encapsulates data of the bottom layer into a frame structure, and a CSMA-CA carrier monitoring conflict avoidance algorithm is planted into the frame structure; the network layer achieves formation, retrieval and input and output control of data packets in the protocol and interface function transmission and reception by calling a software interface encapsulated by the physical radio frequency layer; the application layer establishes an application program interface function capable of achieving all functions of the application layer by calling a software interface provided by the network layer. By means of the wireless sensor network communication protocol method, communication can be guaranteed greatly, work efficiency of the automatic cathodic protection data collection system is greatly increased, management cost is reduced, and transport security of petroleum pipelines is guaranteed.