To solve the problem that the traditional differential protection logic has a slow action speed in the 5G environment, a differential protection method suitable for 5G communication is proposed. First, this paper analyzes the logical principle and action sequence of traditional differential protection when optical fibers are used as transmission media. Secondly, the current communication situation of 5G differential protection is analyzed, and the problems existing in the application of the traditional differential protection logic in this environment are also analyzed. By measuring the network communication delay, the necessity of reducing the number of times of information transmission is analyzed. Finally, the differential protection logic is optimized to reduce the influence of communication delay on the action speed. Through experimental verification, the improved differential protection action time is accelerated by 10~15 ms, which is about the transmission delay of information in the 5G environment. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. 52094020000Y).