5G carrying differential protection service is requirement for the integration and development of communication and protection technologies. This paper analyzes the channel requirements of differential protection with different timing principles, and compares the difference in the delay requirements of differential protection channels in high and low voltage networks. The feasibility of deterministic transmission delay technology and precise timing technology in 5G wireless communication is also analyzed. Differential technology based on 5G accurate time stamp is proposed. The field test of 5G base station verifies that the timing accuracy and transmission delay can meet the requirements of differential protection services. This work is supported by the National Key Research & Development Program of China “Research and Application of Merging 5G Digital Power Grid High-security High-reliability Communication Technology” (No. 2020YFB0906003).