In view of the problem that the magnetic field generated by the external current affects the hot electrons in the mainstream thermal emission electron guns, the laser heating cathode mode was proposed. The heating mode can effectively eliminate the influence of the magnetic field, so as to improve the beam quality and cathode life. Based on Q60-A electron beam equipment,through simulation and experimental verification, the process of laser heating cathode and electron movement are systematically analyzed, and the selection scheme of laser and the structure optimization scheme of beam source components are determined. The results show that the recommended laser wavelength is 1 064 nm,the operating temperature of the cathode is 2 650 K, the laser power required to reach the operating temperature of the cathode is 377 W, and the critical power to maintain the operating temperature of the cathode is 160 W. The structure size of the new beam source components is optimized. The distance between anode and cathode is 18 mm, the anode aperture is 10 mm, and the radius of grid sphere is 20 mm. The electron beam quality is ideal at this time. The accuracy of simulation results and the rationality of laser selection are verified by experiments. This study provides reference and useful guidance for the systematic design and engineering application of the laser heated cathode type electron gun.105