The utility model discloses a multistage oil -gas separation device, including shell, first motor, second motor and air exhauster, it has set gradually first baffle, second baffle and third baffle to follow the left hand right side in the shell, between first baffle and the second baffle, all be equipped with the filter core between second baffle and the third baffle, the fixed a plurality of lug that is provided with on the left side wall of the right side of first baffle wall and second baffle, the left side of first baffle is equipped with the intake pipe, is equipped with in the below of perforated plate and leads the oiled -plate method, is equipped with the oil extraction funnel on the right side of leading the oiled -plate method, be equipped with the condenser pipe on the right side of third baffle, the wall mounting has temperature sensor on the right side of shell. The utility model discloses at first filtering the great oil of diameter through the perforated plate and dripping, the rethread sets up a plurality of filter cores and crosses the oil strain and drip, and the gas mixture after the filtration receives the condensateization, carries out the edulcoration along with the condensation of vapor with harmful impurity, and water oil separating is thorough, protects the environment.