本文对多轴全挂车转向过程中车轮运动规律进行了分析，找出滑移量的计算方法。用优化理论和铰接四杆机构通用分析方法对多轴全挂车转向机构进行优化设计。有多种目标函数可供选用，既可使转用误差最小，又可使滑移量最小。优化结果已用于某车辆厂的产品中。本文对多轴汽车转向系的优化设计也有一定的参考价值。 This paper analyzes the law of wheel movement during the steering of multi-axle trailer, and finds out the calculation method of slippage. Optimize the design of steering mechanism of multi-axle trailer with optimization theory and universal analysis method of articulated four-bar linkage. There are a variety of objective functions to choose from, both to minimize the use of error, but also to minimize the amount of slippage. Optimization results have been used in a vehicle plant products. This paper also has certain reference value for the optimization design of multi-axle steering system.