Rotary friction plastic welding machine is usually used to weld two circular thermoplastic work pieces. One work piece is fixed on the bottom mold, and the other work piece is fixed on the fixture on the precision servo rotating spindle. Due to a certain pressure acting on the two On a work piece, through the high-speed rotating friction of the upper and lower circular parts, the friction of the contact surface produced by the upper and lower work pieces is heated up, and the mechanical energy is converted into heat energy. The two work pieces are welded together to become a permanent fusion and form a tight and airtight whole, meeting the welding requirements.