The transformation of the dissimilar metals in the welding area into a single metal is an important method for achieving high-quality welded connection in the dissimilar metal laminated composite plate. In this study, a high-performance titanium/steel composite plate (TSCP) with pure titaniumization in the welding area was prepared by cold spraying, hot rolling and heat treatment processes. The results indicate that cold spraying achieves effective pre-composite deposition of titanium particles while inhibiting interfacial oxidation and Fe−Ti alloying reactions, producing a relatively dense pure titanium coating with a low porosity of only 1.2%. Hot rolling eliminates internal defects and promotes strong metallurgical bonding of the composite interface. The heat treatment promotes the recrystallization and reduces the dislocation density within the coating. The interfacial bonding strength of the welding area with pure titaniumization of TSCP is 257 MPa, and the tensile strength of that is 414 MPa, reaching 95.6% of the TSCP’s base material.