The utility model provides a deodorizing device for cowsheds. The device comprises an exhaust fan, an exhaust deodorizing filter, an air inlet fan, an exhaust transducer, an air inlet transducer, a control system, a control switch, a deodorizing cabinet, an exhaust volume regulating valve, an air inlet volume regulating valve, a deodorizing pipeline and an air inlet pipeline, and is characterized in that the exhaust volume regulating valve is connected with the exhaust fan through the deodorizing pipeline; the air inlet volume regulating valve is connected with the air inlet fan through an air inlet pipeline; the control switch is arranged on the deodorizing cabinet; the exhaust deodorizing filter is arranged at the outlet of the exhaust fan; the control system is connected with the exhaust transducer, the air inlet transducer, the control switch, the exhaust volume regulating valve and the air inlet volume regulating valve; the exhaust fan is connected with the exhaust transducer; the air inlet fan is connected with the air inlet transducer. According to the device, air inlet and exhaust are performed to a closed cowshed, so that the exhaust volume of indoor air can be minimized while the operation of the deodorizing cabinet is guaranteed, and harmful gases generated by cow dung and the like in the cowshed can be exhausted.