The utility model discloses an automatically safe shutdown protective device for engines, which comprises a power supply end, wherein both ends of the power supply are connected in parallel with a water temperature control relay and an engine oil pressure control relay, the output end of a normally open contact of the water temperature control relay is connected with a protective relay, the output end of a normally open contact of the engine oil pressure control relay is connected with the protective relay and a normally closed contact of the protective relay is the output end. When the water temperature control relay of the device is connected with a water temperature sensor of a vehicle, and the engine oil pressure control relay is connected with an engine oil pressure sensor, the normally closed contact of the protective relay of the device can be the output end to connect with an ignition switch of a vehicle. During the working process of the engine, when the cooling water temperature and the engine oil pressure become abnormal, the engine can automatically stop working. The utility model effectively prevents faults from spreading and resulting in gadget damage, protects safe working of engines, extends service life of engines, enhances work efficiency and avoids gadget accidents when people drive.