Abstract:A high-power electron gun for welding was designed by using LaB6 indirect thermal cathode and using the integrated iteration method. On the basis of theoretical design, the initial structural parameters were optimized and adjusted through the Source module in the Munro software. In the end, the design index of power 36kW, acceleration voltage 100kV, emission beam current 360mA, beam waist diameter 300μm was reached. A large number of simulation experiments were carried out using the single variable method. The relationship of the grid position, grid aperture, grid voltage, anode position, anode aperture of the electron gun and the size of the electron beam and the beam waist diameter was summarized. This has certain guiding significance for the adjustment and optimization of the structural parameters of the three-pole electron gun.