Abstract: A large area quartz crystal wafer lapping device, provided with a base, a supporting arm assembly, a lapping plate, a swivel gantry, a rotating motor, a loading block and a plate-Adjusting ring; The supporting arm assembly comprises a swing arm, a swing arm shaft, a swing arm motor, an adjustable arm and a roller; The swivel gantry is driven to rotate by the rotating motor; The loading block is encased in the plate-Adjusting ring, and a quartz crystal wafer is bonded to the bottom surface of the loading block. In the invention, through the improved design of material removal and wafer retention, the processing surface shape of large area quartz crystal wafer can meet the design requirements.