The invention discloses a novel manufacturing technology of a super-large size gear steel SCM822H for industrial speed reducer, and aims to provide gear round steel blanks for super-large size gear (Phi 700-980 mm) to meet the internal quality requirements. A high purity steel smelting technology is adopted, and the internal control compositions are optimized. An upsetting and rolling technology and a large deformation forging technology are adopted, and the temperature of final forging is controlled below 930 DEG C. The annealing and normalizing are performed in several sections. The technology route comprises the following steps: steel making (electric furnace), external refining (LF and VD), ingot casting, forging (3150t quick forging press or 3500t quick forging press), heat treatment, and flaw detection. The technology has the advantages that by controlling the chemical components and smelting technology, the mechanical properties can be guaranteed, and hardenability and inclusion are stable and qualified; the aluminum is controlled in smelting, in forging, upsetting and rolling, the grain size is not less than six grades; the hydrogen is removed through smelting VD, vacuum degasifying, and a unique steel annealing technology; and the problems of purity, performance, hardenability, grain size, and white spot of large size gear steel are solved.