From the analysis of experiment data of the multi-axle vehicle chassis searching process,it is less accurate to predict multi-axle vehicle dynamic characteristic with simplified two-axle vehicle model.So it is important to find out a more effective modeling method in the study of multi-vehicle stability.In the development of heat transfer fluid(HTF) six-axle vehicle,a whole vehicle multi-body dynamic model is built through collaborate flowchart using Teamcenter Engineering,UG NX3 and MSC.Adams.The modeling method of connected hydragas spring suspension is validated by running test results.Based on this whole vehicle model,a kinematical analysis of suspension is implemented to achieve optimized suspension geometry parameters according to the stable requirement.Then, different handling simulations are carried out with regard to various tire characteristics,driving con- figurations,and equipments.According to the evaluation of whole vehicle handling characteristic, some design rules are summarized to improve the stability of multi-axle vehicle. From the analysis of experiment data of the multi-axle vehicle chassis searching process, it is less accurate to predict multi-axle vehicle dynamic characteristic with simplified two-axle vehicle model. So it is important to find out a more effective modeling method in the study of multi-vehicle stability. in development of heat transfer fluid (HTF) six-axle vehicle, a whole vehicle multi-body dynamic model is built through collaborate flowchart using Teamcenter Engineering, UG NX3 and MSC. Adams. connected hydragas spring suspension is validated by running test results. Based on this whole vehicle model, a kinematical analysis of suspension is implemented to achieve optimized suspension geometry parameters according to the stable requirement. Chen, different handling simulations are carried out with regard to various tires characteristics, driving con- figurations, and equipments. According to the evaluation of whole vehicle handling characteristic, some design rules are s ummarized to improve the stability of multi-axle vehicle.