Positioning device for lens polishing

The utility model discloses a positioning device used for lens polishing, which comprises a planet wheel and a lens, the left side and the right side of the front side face of the planet wheel are respectively provided with a clamping mechanism, and the two clamping mechanisms are clamped on the two sides of the lens, the left side and the right side of the front side face of the planet wheel are respectively provided with a fixing plate, and a first screw rod is screwed in each fixing plate. The left end of the first screw is connected with a second screw through a first rotating piece, the left end of the second screw is connected with an elastic piece through a vertical plate, the second screw is in threaded connection with an internal thread ring, the internal thread ring is connected with a moving ring through a second rotating piece, and connecting rods are installed at the upper end and the lower end of the left side face of the moving ring. When the diameter of the lens changes, the connecting rods ca