Plug-in hybrid electric vehicles (PHEVs) have been seen as promising vehicles which have merits of hybrid electric vehicles and electric vehicles. Because of difficulties of plug-in hybrid electric vehicles’ development, it is necessary to study revamped method on the base of original car. Electric power steering (EPS) is an advanced steering system that uses an electric motor to provide steering assist. Because PHEVs are often on electric-electric operating mode, steering system power should be supplied with electric motor. Also, reconfigration of the power system including batteries results in added weight and the load change on front axle and rear axle. The steering characteristic of the revamped car are different from that of the original car. Based on the analysis and actual size, mass-force, etc. of the overall car and the parts of EPS, the multi-body dynamic model of the car equipped with EPS is established with multi-rigid-body dynamics analysing software (ADAMS). Based on the virtual prototype, simulation of steady state steering characteristic and transient state response characteristic of revamped car compared with original car under angulus step input of steering wheel have been finished. According to the simulation results, steering characteristic of the revamped car meets the design requirements. The research method is feasible.