The invention discloses a stirring paddle which comprises a hub, a disk and blades, wherein the blades and the disk form an integrated structure, and the disk is fixed to the lower part of the hub. The stirring paddle disclosed by the invention adopts the expanding connection mode, thereby effectively avoiding the problem of metal swealing defect caused by conventional argon arc welding, effectively ensuring the dynamic balance properties of the stirring paddle, and ensuring the rotation stability of the stirring paddle; the processed stirring paddle has accurate size, thereby avoiding the dimensional discrepancy of the formed stirring blade due to uncertainties in the manufacturing process, lowering the influence on the culture process and experimental results, and being beneficial to the parallel experiment by using the minitype bioreactor.