The invention provides a ratchet stop mechanical prosthesis based on 3D printing and provided with air bags and a using method and relates to the technical field of prosthesis. The ratchet stop mechanical prosthesis based on 3D printing and provided with the air bags comprises a prosthetic finger part, a prosthetic palm part, a prosthetic wrist part, a prosthetic forearm part and a residual limb connecting part which are connected in sequence, wherein the prosthetic finger part comprises a splint I and a splint II which are arranged oppositely, the air bags are arranged on the inner sides of the splint I and the splint II, the splint I is fixedly connected with a gear I, the splint II is fixedly connected with a gear II, and the gear I and the gear II are engaged to drive the splint I andthe splint II to be opened and closed; the prosthetic palm part comprises a connecting plate I, a connecting plate II, a clamping mechanism for controlling the splint I and the splint II to be clampedand a link mechanism for controlling the splint I and the splint II to be loosened. The ratchet stop mechanical prosthesis based on 3D printing and provided with the air bags and the using method have the advantages that the structure is simple, the weight is light, the cost is low, and soft grabbing hand feeling is realized by the aid of the mechanical structure.