An oscillating combined steering mechanism was introduced. With Denavit-Hatenberg homogeneous transformed matrix, the kinematics model of the steering mechanism was constructed. The multi-objective optimization method for designing the location of key hinge was proposed. The engineering illustration of steering mechanism was calculated, and the result was proved by the ADAMS software. Some characteristics of steering mechanism, such as the asymmetry of steering drive oil cylinder control, steering smoothness, skidding behavior, and symmetrical distribution were analyzed. The proposed method was reliable and simple, and had important practical value for engineering applications. The steering mechanism had some merits, such as small turn radius, little side slide, easily controllable, it will have wide applied range in engineering vehicle.