Abstract: The laser welding test was carried out on the electron gun of microwave tubes. The weld surface morphology, microstructure, interface element distribution, fracture morphology, main phase, hardness, mechanical properties, vibration and electrical property were studied by metallography microscope, scanning electron microscopy, X-ray diffraction, electron micro-hardness analyzer, vibration table and vacuum degassing system. The results indicated that the morphology of welding surface could be improved through the optimised welding parameters and the electron guns survived in continuous high temperature working condition. The vibration and electrical property test examined the welding quality for the electron guns. Meanwhile, the reliability of laser welding process in the development, production, and application of microwave tubes has been verified.