Protective clamping jig for main board machining

The utility model discloses a protective clamping jig for mainboard processing in the technical field of mainboard processing, which comprises a fixed seat and a sliding chute, the sliding chute is embedded in the surface of the fixed seat, a sliding block is arranged in the sliding chute, the sliding block is in sliding connection with the sliding chute, a threaded rod is arranged in the sliding chute, and the threaded rod is in threaded connection with the sliding block. One end of each threaded rod is provided with a rotary knob, the rotary knobs are fixedly connected with the threaded rods, the tops of the sliding blocks are provided with clamping blocks, the clamping blocks are fixedly connected with the sliding blocks, one side of each clamping block is provided with a first soft cushion, the top of the fixing base is provided with a clamping plate, the clamping plate is fixedly connected with the fixing base, and one side of each clamping plate is provided with a second soft cushion. The mainboard fixi