In order to improve the kinematics curves of slider for cold and warm forging press and the quality of forgings , the link parameters of transmission mechanism were optimized. Then, based on the kinematics model of transmission mechanism for six-link cold and warm forging press, combining with the actual engineering design constraints, taking the maximum height, the rapid return characteristics and the maximum acceleration as optimization targets, the unified objective function was got by the method of linear weighting, and the engineering optimal solution was obtained by the optimization algorithm combining penalty function and complex method. Furthermore, in the process of constructing the multi-objective function, a dimensional conversion function was put forward, and the optimized main technical indexes and the kinematics curves of slider were compared with the results optimized by common dimensional conversion function. The results show that the maximum height of mechanism is reduced by 3.6%, the return time is shortened by 10.3%, and the speed at 15 mm before the bottom dead point is reduced by 12.4%, which show that the dimensional conversion function is superior to the common dimensional conversion function and has certain reference value.