Abstract: The installation of high-voltage capacitors is mainly done manually, which is difficult to lift and carries high risks of disassembly and assembly. It requires multiple people to cooperate, which is time-consuming and laborious, seriously affecting the efficiency of operation and maintenance work. Based on this, this article designs a fast replacement device for high-voltage capacitors in limited space, mainly including two parts: transmission structure and support structure. Among them, the transmission structure is equipped with vertical and horizontal transmission devices, which facilitate the lifting and entry and exit of capacitor modules, eliminating the problems of difficult handling and easy dropping, and can improve the efficiency of maintenance work; The supporting structure adopts welded frames and leveling elements to ensure that the high-voltage capacitor quick replacement device has sufficient safety factors during the operation process, which can strengthen on-site operation control. This device has significant practical value and is worthy of in-depth research and expanded application.