A vertical high-precision post processor for a plastic pipe is characterized by comprising a rack; an upper fixing plate and a lower fixing plate are arranged on the rack, a bearing bush is arranged in the upper fixing plate, bearings are arranged in the bearing bush, the inner walls of the bearings are connected with a copper bush shaft, a tool rest supporting plate is arranged outside the upper end of the copper bush shaft, tool rest supporting rods are arranged on the tool rest supporting plate, a tool rest ring is arranged on the tool rest supporting rods, and blades are arranged on the tool rest ring; bearing locking nuts, a driven gear and gear locking nuts are arranged on the part, located at the lower ends of the bearings, of the outer wall of the copper bush shaft in sequence; a large motor is arranged in the rack and connected with a driving gear, the driving gear is meshed with the driven gear, guide columns are arranged between the upper fixing plate and the lower fixing plate, guide sleeves are arranged on the guide columns, a sliding plate is arranged on the guide sleeves, a vertical adjusting block is arranged on the sliding plate, communicated screw holes are formed in the vertical adjusting block and the sliding plate, a screw is arranged in the screw holes, a small motor is arranged below the lower fixing plate, an output shaft of the small motor is connected with the screw, a chuck is arranged on the vertical adjusting block, clamping grooves are formed in the chuck, clamping bases are arranged in the clamping grooves, and the clamping bases are matched with the inner wall of the plastic pipe.