Platform fully enclosed combination design. The direct locking mechanism of tibia polymer polyethylene gasket can avoid metal ionization caused by traditional metal ring locking mechanism and greatly reduce the extra wear caused by slight movement. The triangular keel tibial platform is designed to minimize rotation of the tibial base and increase stability. Keel protuberance design can maximize the contact area, reduce local bone load, effectively prevent subsidence; The seven prosthesis sizes can meet the needs of matching degree of prosthesis installation to the greatest extent.