Abstract: The laser shot peening technique of 1Cr14Ni3W2VB/1Cr18Ni9Ti dissimilar stainless steel argon arc welding butt joint was studied, and the influence of different laser shot peening parameters on the microhardness, residual stress, microstructure and vibration fatigue life was compared and analyzed.The results show that after laser shot peening, the surface compression stress of the samples increases significantly, reaching maximum of 259 MPa, and the stress is compression stress within about 1 mm depth from the surface.With the increase of laser shot peening energy, the residual compressive stress of the laser shot peening sample increases.After 8 J of laser shot peening, the grains of the heat affected zone of the joint are obviously refined, and the microhardness increases obviously, the vibration fatigue life of the sample increases by 2.57 times compared with that of the sample before laser shot peening.The technology is successfully applied to the repair of an aero-engine pressure sensor, which ensures the reliability of the pressure sensor.