The invention discloses a stirring device with arc-shaped blades, wherein the stirring device comprises a fixed frame; a tank body is arranged on the fixed frame, and the bottom of the tank body is provided with a discharge pipe; the discharge pipe is provided with a valve; the top of the tank body is provided with a motor; a power output end of the motor is connected with a rotating shaft; the rotating shaft is arranged inside the tank body; the rotating shaft is provided with a plurality of stirring blades from top to bottom successively; the stirring blades are upwardly convex arc-shaped plates, and the projection widths of the top-down stirring blades in the horizontal direction are increased gradually; the top of the tank body is at least provided with 2 feed ports. The stirring blades are set into the upwardly convex arc-shaped plates, and the projection widths of the top-down stirring blades in the horizontal direction are increased gradually, so the stirring blades with the structure not only can be used for stirring a liquid, but also can play a buffer role when the liquid enters the tank body, to avoid damage to the bottom of the tank body.