Nowadays, road test simulation on test rig is widely used in the car industry to shorten the development circles. However, there is still room for improvement of the time cost of current road simulation test. This paper described a new method of shortening the time of road test simulation on multi-axial test rig. In this paper, road load data of a 4x2 heavy truck axle have been collected from a proving ground road test, which include the forces and torques of wheels, strains on axles, three directions of accelerations on wheels and displacements between the frame and axle. The total channels reached 35 for each axle. Then the fatigue editing technique is applied to cut the small load to reduce the simulation test time initially. The edited road load data is reproduced on multi-axial test rig successfully. The rainflow counting matrixes of strains on different proving ground roads are established by rainflow counting method, then the matrixes are transformed into damage matrixes based on standard S-N curve and Miner rules, ignoring the effect of mean load. According to the proving ground requirements, a standard proving ground test simulation for vehicle reliability procedure is established. The rainflow and damage matrix of the standard procedure can be achieved using rainflow extrapolation. With the test time of each road and the damage matrixes, the multi-objective optimal model is built based on the principle of equivalent damage. Optimization objectives are minimizing the test time of the result and the damage matrix error between the standard and the results. The multi-islands genetic algorithm is used to solve the problem. The Pareto curve of the two optimization objectives (errors to test time) showed that a high accelerate ratio corresponds to a relative high damage equivalent error.