Lightning strike tripping of transmission lines poses a serious hazard to the safe and stable operation of power grids, and this paper carries out a research on lightning strike risk assessment and differentiated lightning protection transformation for a 110 kV transmission line. We obtained line tower parameters, ground flash data, terrain elevation, etc., using the improved EGM and ATP electromagnetic transient simulation to calculate the winding lightning with-stand levels, rebound lightning withstand levels and trip rates, fine assessment of the lightning risk of 57 towers, put forward based on multi-factor quantitative grading of tower high-risk cause finding and lightning protection and renovation measures refinement of the intelligent recommendation method process, effectively improving the de-cision-making efficiency, taking into account the technical economy of various types of measures. The results show that all 27 high-risk towers on the line are reduced to low risk after differentiated lightning protection. This paper can provide a reference for the lightning protection of electric power system.