The invention discloses a testing device and a method for a sub-module of a crimping type IGBT module. The device comprises an emitter lead-out end, a gate lead-out end, a collector lead-out end, a pressure block, a test chamber, and a screw. The upper surface of the pressure block is configured with a screw contact portion, and the lower surface of the pressure block is configured with a gate contact portion and a protruding pressure head of the pressure block. The gate contact portion is connected to the gate lead-out end. The pressure head of the pressure block is connected to the emitter lead-out end. The top of the inside of the test chamber is configured with a threaded screw placement opening, and the bottom of the inside of the test chamber corresponding to the screw placement opening is configured with a placement portion for arranging the sub-module to be tested of the IGBT module. The screw has the threads, and is matched with the screw placement opening. The device of the invention is matched with the sub-module of the crimping type IGBT module, can assist existing test equipment to test the sub-module of the crimping type IGBT module. Compared with the equipment in theprior art, the device of the invention has the advantages of simple structure, simple use, and high practical value.