To validate the communication performance of the adaptive protection system of power supply and distribution line， the system's communication network is constructed based on DeviceNet fieldbus and industrial Ethernet. Transmission time delay model and performance evaluation indices of fieldbus are presented. Transmission time delay， throughput， network efficiency and network utilization of DeviceNet communication of the system are evaluated. Constitution of transmission time delay and general formulas of industrial Ethernet are presented. Transmission time delay of industrial Ethernet periodic communication of the system is analyzed. Results of simulation indicate that the real time performance and reliability of DeviceNet and industrial Ethernet communication of the system can satisfy the requirement of substation automation.