Multi-beam electron beam welding (EBW) is a new technique that allows more than two electron beams running simultaneously for welding and it is considered a promising method to reduce welding stress and deformation. In order to reduce the deformation of Ti6Al4V alloy sheets, a novel multi-beam EBW method is proposed in this study, besides one main electron beam to melt metals, also including two additional electron beams to post-heat the weld. Experiments were conducted on Ti6Al4V alloy sheets using this multi-beam technique. Results show that compared with the conventional EBW, the multi-beam EBW can improve the welding thermal cycle and effectively reduce the welding deformation by adjusting the position and energy distribution of two additional electron beams.