Based on the characteristic of malleable iron, the technology of multistage heat treatment for malleable iron was investigated successfully. Compared with the present technology, the time of graphitizing annealing using new process was saved about 50% . The microstructure, with uniform distribution of fine polycrystal of graphite nuclei and full elimination of carbide, was obtained. Comprehensive mechanics performance of product exceeded that of present international standard . Two brands of KTH400 — 12 and KTZ750 - 02 can be added on the base of present international and “malleable iron” standards. Those products, such as line tool, pipe fitting for railway, engine piston of car etc, with better performances and credible qualities treated by the technology, were welcomed by users.