Abstract: Elaborated in the paper are the algo rithm principle and the system functions of the Delphi-based general-purpose computer design software for the MPM pass. With the roll pass design software,data of the 173 pass are designed,and then compared with the original parameters of the pass as provided by INNSE. The result shows that using of the said software leads to correct algorithm of the parameters of the pass and the cross section of the pipe, which can be adapted as the basis for instructing the development of new passes. The above mentioned CAD pass design process will play a significant role in improving efficiency of pass design,product surface quality and dimensional accuracy,and rolling force and energy consumption,etc of the mill.