The invention discloses a smoke purifying device for agricultural waste incineration. The device comprises a tank, wherein an incineration box is fixedly connected with the bottom of an inner wall of the tank; an absorbing tank is fixedly connected with one side of the inner wall of the tank and is located on the left side of the top of the incineration box; a disinfecting box is fixedly connected with the right side of the inner wall of the tank and is located on the right side of the inner wall of the incineration box; a first motor is fixedly connected with the top of the inner wall of a top box; a moving device is fixedly connected with an output shaft of the first motor; and the top of the moving device is fixedly connected with the top of the inner wall of the top box through a fixing plate. The invention relates to the technical field of agricultural waste treatment equipment. The smoke purifying device for agricultural waste incineration can effectively disinfect the harmful matters in the smoke, can prevent the harmful matters from being directly emitted and polluting environment, can greatly reduce the environmental pollution, can reduce unnecessary waste, can save the cost, has a simple structure and is easily operated.