The microstructural characterization and interfacial shear tests of Ti/Steel bimetallic clad sheets were taken to study the interfacial bonding mechanism during explosive welding process. The wavy interface with several vortexes forms between the dissimilar metal matrixes due to the interface deformation. A significant metal flow of steel matrix caused by the severe plastic deformation induces the continuous vortexes in the interface. The TEM and XRD analysis clarify that the nanoscale interfacial interlayer contains solid solutions and a small amount of intermetallic compounds. The shear strength of the interface along the explosive welding direction is enhanced by the wavy interface. The fracture of the bonding interface presents the ductile features on the vortex and while brittle features on the smooth interface.