An integrated batch planning mathematical model based on multi-object optimization is proposed to solve the orderly and efficient flow of material between different working stations in iron and steel enterprises, where production technology constraints, material variations and coupling between steelmaking-continuous casting and hot rolling are analyzed first. According to the requirements of the hot rolling steel strip contracts, the integrated batch planning is divided into sub-plans of rolling plan, casting plan and furnace plan which are independent and coupling to each other, forming rolling plan and furnace plan simultaneously to influence casting plan. Heuristic method based on modified co-evolutionary algorithm is advanced to resolve this problem. The results of simulation and analysis in an iron and steel plant for strip steel production shows that it is feasible to provide effective guidance for integrated batch plan making.