Mainboard machining jig

The utility model provides a mainboard processing jig which comprises a discharging box body, a mainboard placing carrier plate and an overturning cover plate, the mainboard placing carrier plate is arranged on the discharging box body, a limiting placing cavity used for limiting a mainboard is formed in the mainboard placing carrier plate, and the overturning cover plate can cover the limiting placing cavity after overturning towards the mainboard placing carrier plate. A discharging contact is arranged on the face, facing the limiting containing cavity, of the overturning cover plate, and after the overturning cover plate covers the limiting containing cavity, the discharging contact can abut against the main board. According to the mainboard machining jig, the time for discharging the mainboard can be utilized, screw locking operation of the mainboard can be synchronously completed, the assembly efficiency of the mainboard is greatly improved, and the mainboard can be prevented from being electrified. 本公开提