The invention relates to a cylinder linear motor. The cylinder linear motor comprises a primary structure, a secondary structure, multiple sets of thirteenth salient pole structures, multiple third permanent magnets, multiple fourth permanent magnets, multiple first windings and multiple second windings, wherein the primary structure and the secondary structure are cylindrical structures, the primary structure is sleeved outside the secondary structure, the primary structure and the secondary structure are coaxially arranged, the multiple fourth permanent magnets are mounted on an outer wall of the secondary structure, one ends of the thirteenth salient pole structures are mounted on an inner wall of the primary structure, and the multiple third permanent magnets, the multiple first windings and the multiple second windings are mounted on the multiple sets of thirteenth salient pole structures. The windings are arranged on the static side of the primary structure, so the structure of the secondary structure is made to be simple, cost is reduced, moreover, the secondary structure is disposed in the sea water, corrosion to the magnet windings is avoided, maintenance is convenient, reliability is high, the permanent magnets used for having the auxiliary effect are all arranged on the secondary structure, and the magnetic field of the linear motor is further improved.