Electrified railway in China has been actively developed. At the same time, as a kind of impact load, the load of electrified railway traction substations has brought a significant impact to the accurate measurement on the electric power energy metrology. This paper measured and analyzed the field electric power parameters of several electrified railway traction substations, and analyzed the causes of the metrology result difference between the impact load electric energy meter and the ordinary electric energy meter. The research work laid a foundation of the popularization and application of non-conventional energy load accurate metrology technology.