The utility model discloses a continuous rectification under vacuum of cadmium condenser for stove, the inboard coolant tank who is sealing saddle in its condenser upper portion, recirculated cooling water from coolant tank entry inflow is followed the coolant tank export again and is flowed, its characterized in that, the condenser top is equipped with the connection for vacuum pump with vacuum pump connection, and condenser low lower to one side is equipped with the export of cadmium liquid, is equipped with cadmium steam inlet near cadmium liquid export side, connection for vacuum pump department is equipped with inspection cover and cooling jacket, the inside several cadmium steam diversion separator plate that are equipped with crisscross installation of condenser are equipped with at least one heating pipe sleeve pipe between the steam diversion separator plate clearance, several heating pipes are respectively installed to two the big sides and the low -side of condenser. This device can effectively promote condensation efficiency to prevent that the cadmium from blockking up condenser and vacuum extraction opening pipeline, simple structure.