Abstract: The design process of the currently-used equal-arm three-roll mandrel steadier stays with such problems as long design work cycle and low design accuracy,etc. To optimize the said design process,based on relevant mechanical principle,the math model of an equal arm three-roll mandrel steadier with a structure designed as a four linkage mechanism with a drive ratio of-1 is set up. Furthermore,the math model is optimized with the Matlab optimizing tool. Owing to the optimized design,the overlap ratio between the actual center of the above mentioned mandrel steadier and the rolling center is enhanced,the drive conditions improved,the design work cycle shortened,and the service life extended.