The invention discloses an assembling mechanism of a power supply module. The mechanism comprises a work bench. An upper surface of the work bench is provided with a processing position. The upper surface of the work bench is provided with a tool box and a part box. A rectangular operation plate is arranged above the processing position. The operation plate is connected to the processing position through telescoping rods. There are four telescoping rods. The four telescoping rods are arranged below a lower surface of the operation plate. Top ends of the telescoping rods are connected to the operation plate. Bottom ends of the telescoping rods are connected to the processing position. The operation plate is used to assemble the power supply module. The operation plate is provided with a circuit board and four L-shaped limit blocks. The four limit blocks are used to limit the circuit board. The four limit blocks are provided with a first threaded hole. The operation plate is provided with several second threaded holes. The four limit blocks are connected to the circuit board through screws. The structure is simple, operation is simple, an assembling function of the power supply module can be realized, and power supply module assembling efficiency is greatly increased.