Fiber laying costs are high and its popularity is low. These factors limit the large-scale promotion of differential protection in distribution networks. The high performance and commercialization of 5G provides a rare chance for solving the above channel problem. Through theoretical analysis and calculation, the requirements for a communication channel of differential protection are presented, including rate, delay, reliability and security of the channel. Then, the technical basis for 5G-based differential protection is introduced and analyzed. This mainly discusses network slice, slice architecture, and the security system when used for the power grid. Finally, through analyzing the main performance index of 5G, it can be concluded that 5G has good adaptability to differential protection of a distribution network, and can replace optical fiber to become a new communication channel. This work is supported the National Natural Science Foundation of China (No. 51877127), and the Science and Technology Project of Shandong Electric Power Company (No. 5206011900DG), and the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. 5100-202055018A-0-0-00).