The invention discloses a precise and heavy-load type involute beveloid gear-enveloping hourglass worm transmission. The precise and heavy-load type involute beveloid gear-enveloping hourglass worm transmission comprises a gear and a hourglass worm, wherein the gear is made of a hard-tooth-surface wear-resistant material, the tooth surface of the gear is an involute surface, and gear teeth are wedge-shaped along the axial direction thereof; the hourglass worm is made of a medium-hard material, and the tooth surfaces of the both sides of the hourglass worm are enveloping surfaces taking the involute spiral tooth surfaces of the two corresponding sides of the gear as generatrices respectively, and formed by performing generating motion according to the engagement relationship between the gear and the hourglass worm. The precise and heavy-load type involute beveloid gear-enveloping hourglass worm transmission disclosed by the invention is large in transmission ratio range, high in bearing capacity, high in transmission reliability, easy for realize high-accuracy machining, capable of performing tooth side gap adjustment and tooth surface wear amount compensation by virtue of the movement of the axial position of the involute beveloid gear, and suitable for precise and heavy-load equipment such as elevator traction machines, machine tool indexing tables, industrial robots, radars and gun pitching and rotating systems.