The invention provides a stir mixing device, and relates to a mixing device. The invention solves the problem that the mixing device suitable for mixing materials with big specific gravity difference is lacked at present. The upper end face of a stirring rod is fixedly connected with the lower end face of an output shaft of a motor; an upper cover covers the upper end face of a container main body; the lower end of the stirring rod penetrates a central hole of the upper cover and is arranged on the lower part in the container main body; the stirring rod in the container main body is provided with a spiral blade and a meshed type blade from top to bottom; the upper cover on both sides of the stirring rod is provided with a feeding port and a gas outlet; a first rubber plug plugs the feedingport of the upper cover; a second rubber plug plugs the gas outlet of the upper cover; one end of a bent pipe penetrates the second rubber plug to be communicated with the container main body; a condenser pipe is arranged at the upper end of a bracket; and the other end of the bent pipe is communicated with one end of the condenser pipe, and the other end of the condenser pipe is communicated with a tip pipe, of which the tip is arranged right above a collection bottle. The stir mixing device has the advantages of simple structure and low cost.