The invention discloses a waterproof and stable triode and a preparation method thereof, comprising a tube body, a base pin, an emitter pin, a collector pin, a rubber inner shell, a protective inner shell, a rubber shell, a protective shell, and a locking screw. Hole, locking screw, rubber backing plate, protective cover, heat dissipation grid, heat conduction groove, heat conduction silicone column, heat conduction silica gel plate, positioning groove, positioning column, connection groove, connection block, connection screw hole, connection screw, fixing ring , annular sealing groove, rubber sealing ring and limit ring; the invention optimizes the packaging structure, enhances the waterproof performance of the triode, prevents water seepage during use, protects the insulating layer of the triode, improves the safety of the triode, and optimizes the The heat dissipation structure enhances the heat dissipation performance of the triode, thereby completely conducting the excess heat inside the triode to the outside, avoiding the problem of high temperature overheating of the triode during use, and the static operating point is more stable, ensuring the conductivity of the triode.