In order to improve the accuracy of CAE simulation for vehicle crash safety,the microstructure and hardness distribution of the base metal zone,heat affected zone and nugget zone were characterized by various equipments including field emission scanning electron microscope and vickers hardness tester based on the resistance spot welding of HC340/590 dual phase steel sheets. LS-DYNA software was used to simulate the fracture characteristics of solder joints,and the results were compared with those of tensile testing machine. At the same time,the CrachFEM model material card was modified by the hardness difference in each area of the solder joint. The results show that after modifying the CrachFEM model material card,the simulation results are highly consistent with the experimental results,which can predict the failure characteristics of the solder joint position effectively.