Pulsed electron beam welding is an advanced welding technique in which the beam current is modulated into a pulsed square wave. Compared with the conventional continuous electron beam welding, pulsed electron beam welding can increase the evaporation rate of the welded metal, thereby improving the welding efficiency and increasing the weld depth-to-width ratio. In this paper, the welding experiment of 1.2 mm TC4 titanium alloy sheets were carried out by conventional continuous electron beam welding and pulsed electron beam welding with different frequency. Then, the microstructure and mechanical properties of the welded joint were tested. Results show that pulsed electron beam welding can form welds without fusion defects. As the frequency increases, the weld undercut and backside weld?reinforcement decrease and the surface formation is improved. Due to the change of welding thermal cycle, the pulsed beam flow can accelerate the cooling rate of the molten pool and refine the microstructure grains. Both continious and pulsed electron beam welded joints are broken in the base metal zone during tensile process, so the tensile strength is higher than that of the base metal. The high-frequency pulsed electron beam can improve the plasticity of the welded joint and the micro-hardness of the weld zone and the heat-affected zone. When the frequency is 10 kHz, the elongation after fracture of the welded joint can reach 14.9%, which is about 80% of the base metal, and the microhardness of the welding and heat affected zone are 375 HV and 368 HV, respectively.