Abstract: Smart distribution network differential protection data transmission may generate a large amount of traffic, resulting in increased latency when communicating using 5G slicing technology. In this paper, on the basis of elaborating the principle of 5G smart distribution network differential protection technology, we discuss increasing the protection joint-trip relay to solve the problem of asymmetric bidirectional communication caused by the inconsistent action of the differential protection on both sides, and then we compare and analyze the 5G traffic control methods in terms of resource allocation, communication protocols, transmission mechanisms, optimization algorithms, and transmission modes to illustrate that the adoption of the vectorial differential algorithm and the non-standard R-SV protocol can effectively reduce the traffic generated by 5G communication and meet the delay requirements of smart distribution network differential protection, while the combination of 5G and fiber optics channel method is more reliable in the practical application of differential protection.