Abstract: Mathematical model of metallurgical units were established for bottom blowing smelting ingredients, bottom blowing smelting, bottom blowing smelting waste heat boilers, bottom blowing copper matte converting, copper matte converting waste heat boilers, based on such theories as chemical equilibrium, principles of mass conservation, heat conservation, element allocation constraints, when the metallurgical process computing system development platform (MetCal) was used to calculate the copper smelting process of "bottom blowing smelting-bottom blowing matte converting". A simulation system for the entire double-bottom blowing copper process was developed to calculate the material distribution and heat equilibrium of each control unit, whose results were validated by production dates. The research results showed that the absolute errors between production dates and calculations of Cu, S, Fe, Pb, Zn content in matte in the bottom blowing smelting process were 0.32%, 0.74%, 1.64%, 0.47% and 0.32%, respectively, and those of Cu, S, Fe, Pb, Zn, CaO, Al₂O₃, MgO in the smelting slag were 0.05%, 0.96%, 1.59%, 1.13%, 1.09%, 1.17%, 2.45% and 0.67%, respectively. Those of Cu, S, Fe, As, Sb, Bi, Pb, Zn in the bottom blowing process of blister copper were 0.43%, 0.03%, 0.01%, 0.07%, 0.046%, 0.006%, 0.32%, 0.014%, respectively, and those of Cu, S, Fe, Pb, Zn in slag converting were 1.83%, 0.06%, 11.35%, 11.92%, 2.36% respectively. The above calculations provides the basis for industrial production guidance and industrial design.