The invention relates to a dead load testing device and a dead load testing method for a large anchor handling lift winch. The dead load testing device comprises a main steel cable, wherein one end of the main steel cable is connected with a large anchor handling lift winch to be tested; the other end of the main steel cable is connected with one end of a force measuring device; and the other end of the force measuring device is connected with a fastening device through an auxiliary steel cable. The dead load testing device is simple in structure, convenient to mount and high in structural strength; in a dead load testing process, tools such as weights are not required, a dead load test can be greatly simplified, the test construction efficiency is improved, and the ship manufacturing cost is reduced. In the testing method, the tools such as the weights are not required, a large amount of preparation or tail-in operations due to preparation, installation, adjustment and tool disassembling are avoided, the dead load test is greatly simplified, the test construction efficiency is improved, and the ship manufacturing cost is reduced. Moreover, the dead load testing device is high in test accuracy and easy to operate, and is safe and reliable.