The power quality of electrified railway has become one of the close attentive questions of public electric power systems in China and abroad at present. One of the effective measures to improve the power quality of the electric railway is to install SVC (TCR+FC) equipment in the traction substations. This paper presents the analysis of switching transients of the reactive power compensator, which are important in the design of the compensator for the selection of the elements tension. The simulation model of the compensator is established with PSCAD to emulate the process of the switching transients. The different operational manners of the SVC are investigated in An-ding traction substation of Beijing-Shanghai electrified railway. The simulation has been validated by the comparisons of the computed results with the field measured data.