The present invention discloses a new process of black heart malleable cast iron high-temp. kanking heat treatment. Its main process is that the cast iron blank is heated up to the maximum furnace temp. of about 960 deg.C in the annealing furnace with good insulating property, and then the furnace is shut down for high-temp banking and the furnace temp. is reduced at a small temperature gradient and cooled to tapping temperature. The main advantages of said invention are: its process time is shortened by 20-30%, energy resources can be economized by 20-30%, environment contamination is reduced and labor productivity is raised. Besides, its heat-treated blank quality is high and its material property is stable and can come up to KTH 350-10 by more than 95% and up to KTH 370-12 by more than 90%.