A method for rapidly forming a part using combination of arc deposition and laser shock forging, including: 1) dividing a preforming part model into one or more simple forming units by the simulation system and determining a forming order of the forming unit; 2) controlling, by the numerical control device, an arc welding device to perform a melting deposition forming of a processing material layer by layer on a processing substrate of a motion platform to form a melting deposition layer; 3) controlling, by the computer, a movement of the motion platform to keep a fusion zone always in a horizontal state, at the same time, a pulse laser beam of a laser device to perform a synchronous shock forging on an arc deposition region at a plastic deformation temperature. A device for implementing the method.