The invention discloses an annular gear machining technology. The technology method comprises the steps of: machining racks meeting the requirements of sizes and precision by using a grinding machine, and then cutting the racks into single gear teeth; coating high-strength metal glue on the inner surface of a rim, and sequentially sticking the cut single gear teeth on the rim until one annular gear is formed; then carrying out running-in once by using a gear with corresponding tooth profile, coating the metal glue at gaps of adjacent gear teeth after running-in, then conducting running-in again so as to realize self-positioning of the gear teeth; and after the metal glue is entirely cured, nailing a positioning pin on each gear tooth, thus completing the machining of one annular gear. The annular gear manufactured by the technology is reliable in transmission after being used on a manipulator joint, has rotation error superior to that machined by the original linear cutting technology, obviously reduces the noise, is stable to run and promotes a whole running effect of a manipulator.