The critical problem that Ti/Al dissimilar single-sided high speed FA–MIG welding faced to is the great difference in Ti/Al interfacial structural properties. Laser remelting on the back weld was used to deal with the Ti/Al interfacial heterogeneity and improve the joint mechanical properties. Contrastive analysis was conducted to study the influence of laser offset to the Al side d, laser power q, and welding speed v on the joint structural properties. The results showed that the joint structural properties were greatly influenced by d, q, and v. With optimal parameters of d=2 mm，q=1.3 kW，v=5 mm·s^–1, the Ti/Al interfacial reaction layers thickness of the remelted joint root increased and difference in microstructure in the thickness-direction decreased; the tensile strength of the joint reached >280 MPa, which is approximately 20% higher than that of untreated joints; the tensile fractured surface exhibited fracture mechanism of plastic+ductile mixed.