High-precision combined screw assembly

The utility model relates to a high-precision combined type screw assembly which comprises a screw head, the rod body is fixedly connected with the screw head; the screw positioning piece is arranged in the rod body and used for positioning, the screw positioning piece comprises a guide rod, an elastic piece elastically connected with the upper end of the guide rod and a first magnetic clamping piece enabling the guide rod and the rod body to be clamped, and a sliding limiting block in sliding connection with the inner wall of the rod body is arranged on the guide rod; the second magnetic clamping piece enables the sliding limiting block to be clamped with the inner side of the rod body; and the rotating block is fixedly arranged at the bottom of the guide rod. When the to-be-locked piece needs to be locked and positioned, the guide rod is manually driven to move downwards, so that the second magnetic clamping groove and the second magnetic clamping block are locked; when the guide rod is clamped with the rod