An embodiment of the utility model provides a pressure testing device for an injection molding shell, which comprises a support frame, a testing platform, a feeding device and a pressurizing device, the pressurizing device comprises a power device, an output end of the power device is provided with a lower pressing plate, the lower pressing plate is opposite to the feeding device, the feeding device comprises a feeding sliding seat, and the feeding sliding seat is provided with a pressing plate. A pressure bearing plate is arranged at the upper end of the feeding sliding seat, a tool clamp is arranged at the upper end of the pressure bearing plate, the tool clamp is installed on the pressure bearing plate of the feeding device, and the pressure bearing plate installed at the upper end of the feeding device is pulled out of the pressurizing device through the feeding device so that the tool clamp can be disassembled and assembled. Before testing and after testing can be carried out outside the testing area of the pressurizing device, the situation that workers are injured or a shell to be tested is damaged due to the fact that a switch is accidentally touched is avoided, personal safety is further improved, psychological pressure of the workers is reduced, the tool clamp is pulled out of the testing area through the feeding device for operation, the space is larger, and the working efficiency is improved. The operation is more convenient, and the working efficiency is further improved.