With the rapid development of the Highspeed electrified railway in China, the traction load has an increasingly high proportion of the power load. Because of the specificity of traction load, its power factor is low , in contrary its concomitant harmonics and negative sequence currents generally exceed standard and impair the power quality seriously. This paper analyses four aspects, including traction transformer connection,traction substation power supply mode,power supply voltage level and traction load power quality improvement. Finally, choose the best solution by comparing these options to each other and considering the practical application.