Abstract: A parking device including a base frame, a top frame, four cylindrical poles mounted between four corners of the base and top frames, each of the cylindrical poles having two tubular members slidably mounted thereon, an upper platform fixedly mounted on the tubular members at an upper position, a lower platform fixedly mounted on the tubular members at a lower position, a plurality of first hydraulic cylinders mounted on a bottom of the top frame and drivingly connected with the upper platform, a plurality of second hydraulic cylinders mounted mounted on the base frame and drivingly connected with the lower platform, and a positioning device having a casing mounted on each of the tubular members, solenoid fitted within the casing, a plunger fitted within the casing and a spring arranged between the solenoid and the plunger, the plunger being forced by the spring to go partly into a tube radially arranged within each of the poles through the tubular members.