The invention discloses a modularized high-power pulse discharge welding device, and relates to the technical field of high-power pulse discharge welding. The modularized high-power pulse discharge welding device comprises a power box, an electricity storage box arranged on one side of the power box, and a welding platform arranged on one side of the electricity storage box; and the power box, the electricity storage box and the welding platform are respectively provided with a power supply and control module, an electricity storage-discharging module and an operation platform module, the power supply and control module comprises a control system assembly, a trigger source and a high-voltage power supply, and the electricity storage-discharging module comprises a plurality of energy storage capacitors, a discharging switch and a charging switch. In the modularized high-power pulse discharge welding device, the control system assembly controls the charging switch to be switched on and switched off, so that the high-voltage power supply charges the energy storage capacitors, when the preset amplitude is reached, charging is stopped, the control system assembly sends a control signal to the trigger source, a multi-rod-electrode vacuum trigger tube is triggered, energy of the energy storage capacitors is released into a welding coil, large pulse current is formed, and welding is achieved.