Analyzing the reason of the divergence of traditional iterative method using in schedule design of strip cold rolling. It was indicated that max difference method could solve this puzzledom, the iterative algorithm will converge to the desired result. Using explicit formula to calculate the rolling force, the optimization schedule could be obtained accurately and quickly for all kinds of object functions. An example was also illustrated that the satisfied schedule could be got after 13 iterative calculations with a precision of 7% but only a precision of 20% could be obtained with simple FEM (finite element method).