The invention relates to a titanium-aluminum dissimilar metal high-strength metallurgical bonding electron beam connecting method, which comprises the steps of preparing a connector of a sample to bewelded, and arranging both protruded platforms on two butt-joint surfaces of the I-type connector along a thickness of a welding piece, wherein the two platforms have equal lengths in a length direction and a width direction of the welding piece, and the sum of heights in a thickness direction is equal to a thickness of a butt-joint test plate; secondly, carrying out pre-welding treatment, optimizing electron beam welding parameters, and accomplishing melt-brazing and melting; and carrying out secondary modified welding on adjacent titanium sides of melt-brazing welding seams, wherein the twowelding seams are close to each other but not crossed. According to the connecting method provided by the invention, a dissimilar metal high-melting-point difference characteristic is utilized, secondary welding is carried out beside adjacent melt-brazing welding channels of the high-melting-point titanium sides, and a titanium-aluminum bonding interface is re-melted and modified through a secondary welding temperature field, so that a phase structure at the bonding interface part is optimized, and the fragility of the connector is weakened; and meanwhile, a special connector structure is adopted, so that the bonding structure of welding seam root parts is improved, and the reliability of the connector is improved.