基于功率键合图理论建立了工程车辆全液压转向系统的数学模型。运用20sim键图软件重点研究了全液压转向系统管路的动态特性以及液压管路参数对转向系统动态特性的影响。研究结果表明：对于小管径及长管路转向系统，管路内液阻、液感较大，有利于抑制系统的高频振荡和冲击以增强转向系统的稳定性，但延长了系统的动态响应时间；对于大管径及短管路转向系统，管路液阻、液感较小，系统动态响应较快，但转向系统振荡剧烈，振荡幅度增大，振荡次数增多，不利于车辆的操作稳定性。提高油液的体积弹性模量利于改善系统的动态响应速度和稳定性。研究结果为全液压转向系统的设计及管网动态特性分析提供理论依据。

Based on power bond graph diagram method,the general mathematical model of full hydraulic steering system(FHSS) is established.The dynamic characteristics of hydraulic pipes of the FHSS and the influence of the pipeline parameters on the steering system is mainly analyzed by using 20sim bond graph software.The study results show that for the long and small diameter pipeline steering systems, the fluid resistance and fluid sense get larger,whice is conductive to suppress high-frequency system oscillation and shock to enhance the stability of steering system, but also extends the system's dynamic response time; for the short and big diameter pipeline, the fluid resistance and fluid sense get smaller,the System dynamic response is rapid, but the steering system has a intensive high-frequency oscillation，the oscillation amplitude and frequency increase，which is unconductive to the stability of steering system. Increasing the volume of oil elastic modulus of the system to improve the dynamic response speed and stability. The study results provide a theoretical support for the design of the full hydraulic steering system and pipeline nets’dynamic characteristics analysis.