The invention discloses a sapphire wafer polishing and grinding device, and belongs to polishing and grinding equipment. The sapphire wafer polishing and grinding device comprises a rack, a carrier used for containing a sapphire wafer, a plurality of polishing and grinding mechanisms installed on the rack and a plurality of carrier hold-down and translation mechanisms, the polishing and grinding mechanisms comprise a mounting rack, a polishing and grinding tray and a first electric motor, the first electric motor is connected with the mounting rack, an output shaft of the first electric motor is connected with the polishing and grinding tray, the carrier hold-down and translation mechanisms comprise a mounting plate, a cylinder, a moving base, a connecting rod and an electric motor support connected to the mounting plate, a transverse guidepost is arranged on the mounting plate, the moving base is connected with the transverse guidepost through a first linear bearing, the electric motor support is provided with a second electric motor, an output shaft of the second electric motor is connected to an eccentric block, the two ends of the connecting rod are connected with the eccentric block and the moving base respectively in a hinge mode, the cylinder is installed on the moving base, a cylinder piston rod is connected with a pressure rod pillar, the carrier comprises a pressure plate and a sucker, and a concave hole is formed in the pressure plate. The sapphire wafer polishing and grinding device is good in polishing and grinding effect, stable in processing quality, high in production efficiency and convenient to operate.