Bypass operations were first proposed by the Japanese power sector in the 1970s. Through half a century of engineering exploration and development, bypass operations have achieved relatively sound systems. The bypass operation takes three main forms: bypass cable, transformer vehicle, and generating car. The overhaul of distribution network transformers is the major objective of transformer vehicle work. At present, the study of transformer vehicles has been limited to improving the continuity of power supply. There are fewer analyses of user-side power quality during operations to ensure power supply reliability. In order to provide users with higher-quality power, we use MATLAB software to simulate and analyze the change of power waveform in a distribution network during replacement operations involving a transformer vehicle. On the basis of a controlling variable method, we identify the variables that produce least impact on the power quality of the user side, thereby ensuring high quality and reliability of power supply.