With high-saturation butadiene acrylonitrile rubber sealing and special treatment of seal part surface, the bit has better sealing which can bear 260℃. Low-wear grease improve the lubricity and service life of bit sealing. Put the cylinder into the cone indentation,widening the shaft diameter, and meeting the demand of high-speed drilling. Milled tooth bit adopts optimization design of cutting teeth, with teeth surface strengthened by special wear-resistant alloy.