The invention relates to the technical field of mechanical automation, and discloses a mechanical device for automatically turning over and grinding parts, including a chassis, a power shaft is rotatably installed in the middle part of the chassis, and a grinding disc is fixedly sleeved on the outer wall of the middle part of the power shaft. A first pulley is fixedly sleeved on the outer wall of the upper part of the shaft, and a second pulley is locked in the bottom right chassis of the first pulley, and a rotating shaft is locked in the bottom right chassis of the second pulley. The mechanical equipment for surface grinding parts, through the setting of fixtures, swivel seats, lead screws, nuts, connecting seats and pressure springs, realizes the adjustment and control of parts grinding and installation of new parts. The structure is simple, the equipment cost is low, and it is safe. High performance, through the setting of chassis, power shaft, support frame, spoon frame, short column and gear, the function of grinding and turning over can be realized at the same time with one power source, without manpower consumption, high efficiency, high safety and low energy consumption , strong practicability and easy promotion.