The utility model relates to an impeller of a filter. The impeller comprises an impeller shaft and impeller blades. The impeller is characterized in that each impeller blade is of an open structure, the surfaces of the impeller blades are provided with a plurality of arc-shaped rib plates with pressure relief holes, and a water channel is formed between each two adjacent rib plates. Compared with a traditional impeller, the impeller with simple structure has the advantages that owing to the arc-shaped rib plates with guide grooves, water flow of a pump is greatly improved, water flow resistance is decreased, energy consumption of the water pump is reduced, and the impeller is convenient to machine and low in cost.