The invention discloses an automatic test tool for a front cover of a generator. The automatic test tool comprises a pedestal, an installation hole tester, a control cabinet and a stamping device; thepedestal is provided with a workpiece seat used for accommodation, and the front cover of the generator is accommodated in the workpiece seat; the installation hole tester comprises an infrared beamemitter and an infrared beam receiver; the infrared beam emitter and the infrared beam receiver are arranged at the two sides of the workpiece seat respectively; the stamping device comprises a stamping cylinder and a stamping push rod; the tail end of the stamping push rod is provided with a stamp; the stamping push rod is suspended over the workpiece seat; the stamping cylinder is connected withthe stamping push rod; and the control cabinet is connected with the infrared beam emitter, the infrared beam receiver and the stamping cylinder, and controls work of the infrared beam emitter, the infrared beam receiver and the stamping cylinder. Thus, an installation hole in the front cover of the generator can be detected rapidly. The test tool is simple in structure, easy to prepare, convenient to operation and small in occupation area; and via the test tool, the detection process can be shortened effectively, the detection efficiency is improved, and detection errors are reduced.