The utility model belongs to the technical field of valves, and relates to a check valve, in particular to a dehumidification check valve for engines. The utility model solves the technical problems of conventional check valves, such as poor airtightness. The dehumidification check valve for engines comprises a valve body with a cavity, wherein one end of the valve body is provided with an air inlet, the other end of the valve body is provided with an air outlet, and the dehumidification check valve for engines is characterized in that a blocking body which can move in the cavity and utilize gravity to block the air inlet when the valve body is obliquely mounted is arranged in the cavity. The dehumidification check valve for engines has the advantages of reasonable design, simple structure, good leak tightness, long service life and the like, and can prevent high-pressure air flow from flowing backwards and enhance the heat dispersion of an engine radiator.