Abstract: In order to solve the problems such as insufficient effective penetration and cracking at the weld seam of HR-2 hydrogen resistant steel, a statistical model between the welding process parameters (focusing current, welding speed, beam current, tilt angle) and the predicted response values (effective penetration, joint shear load) of HR-2 hydrogen resistant steel electron beam insertion welding was established based on the response surface method using the BBD design test scheme. It can optimize the welding process parameters according to the requirements of effective penetration and joint shear load, and predict the effective penetration and joint shear load of electron beam plug welding by optimizing the electron beam welding process parameters, so as to achieve the best combination for weld section morphology and joint strength. The results show that the model fits well, the predicted value of effective penetration is 1.17% higher than that of the measured value, and the predicted value of joint shear load is 2.63% higher than the measured value. Better welding parameters are listed as follows: the focusing current is 2.46 A, the welding speed is 10.00 mm/s, the beam current is 8.20 mA, and the tilt angle is 11°. Effective penetration depth of the weld under this parameter is 1 347.82 μm, and shear load of joint is 13.525 kN.