The utility model discloses a reaction kettle, the reactor comprises a kettle, be equipped with installing port and window on the cauldron body, install the light on the installing port, the light passes through mains operated, installing port and the symmetrical setting of window are on the cauldron body, the position is equipped with the masking shield on the window, pass through the masking shield, can prevent that the dust in the air from gluing on the window, guarantee the cleanliness of window, be equipped with control switch between masking shield and the window, be connected through control switch between light and the power, control switch self opens and close through masking shield control, pass through control switch, can control opening and close of transparent lamp, and connect control switch through masking shield and window, the state that is the masking shield in the window position can be opening and close rather than corresponding of control switch, so as to makes opening of shut and close and to control opening and close of light, thereby reach the mesh of practicing thrift the electric energy.