The invention discloses a titanium alloy and kovar alloy dissimilar metal electron beam welding method. The titanium alloy and kovar alloy dissimilar metal electron beam welding method specifically comprises the following steps that (1), a titanium alloy, a kovar alloy, a copper foil and a niobium alloy are taken with the surfaces being cleaned; (2), the titanium alloy, the kovar alloy, the copperfoil and the niobium alloy which are subjected to surface cleaning are alternatively placed in a butt joint manner; and (3), welding is performed, namely the well placed sample is fixed in a clamp and clamped, and is welded by adopting an electron beam welder in a vacuum chamber. According to the dissimilar metal welding method provided by the invention, double transition layers are adopted, solid solution transition is formed at a weld joint by adjusting technical parameters and selecting materials, so that mutual diffusion of titanium and iron elements is prevented; forming of crisp compounds is avoided; and the obtained weld joint has the advantages of being low in rigidity, high in tensile strength, free from pores and cracks and the like.