Abstract: The distribution of the restrain stress in the welded joint zone of HQ130 high strength steel was researched by means of the ANSYS finite element method (FEM).The calculation results indicated that the instantaneous restrain stress on the surface of the weld of HQ130 steel reached 800~1 000 MPa,the instantaneous restrain stress at the bottom of the weld reached 500~600 MPa,under the condition of the gas shielded arc welding and heat input 16 kJ/cm.The stress gradient near to the fusion zone was larger.This is one of the important reasons that result in cold cracks at the fusion zone of the high strength steel.The thermal stress in the welded joint zone can be decreased by controlling welding heat input,and can prevent the welding cracks.