Impeller for stirrer

The invention discloses an impeller for a stirrer. The impeller comprises stirring blades which surround a stirring shaft and are arranged in an axial external expansion mode, wherein an included angle is formed between each stirring blade and the stirring shaft, and the tip end of each included angle faces downwards. The stirring blades are arranged in the axial direction in an outward expanding mode, the included angle with the tip facing downwards is formed between each stirring blade and the stirring shaft, when the impeller rotates, a conical cavity is formed between the stirring blades and the stirring shaft, fluid flows into the conical cavity along the stirring blades and then generates a spiral upward movement track, the lifting force of the impeller in the stirring process is greatly improved, and high-density substances in the chemical reaction tank are prevented from precipitating at the bottom of the tank, so that the high-density substances can be recycled; and a small part of fluid is thrown ou