The QJ double-arc blade impeller is used for stirring in dish-shaped or elliptical containers. The concave shape in the upper middle part is suitable for the installation of bottom bearings or upward-expanding discharge valves, which can partially eliminate bottom vortices. It is suitable for low-viscosity mixing, dissolving, crystallization, or high-viscosity, large-diameter, and XJ multi-layer combined low-speed stirring.