Laser cladding deposition is used to fabricate the Ti40 (Ti-25V-15Cr-0.2Si) flame-retardant layers on the surfaces of traditional TC4 alloys. Further, the composition, microstructure, and microhardness distribution of the cladding layer are subsequently investigated. Subsequently, theoretical methods are established for predicting the dilution rate and composition of transition zone of cladding layer under different laser powers. The experimental and analysis results show that there is a transition zone with respect to the composition and microhardness at the interface between the TC4 matrix and the Ti40 laser cladding zone; in 300-350 μm of the transition zone, significant composition and microhardness changes are observed under four laser powers. Among the four laser powers, the laser power of 1800 W results in the most substantial changes with respect to the microhardness and element contents of Al, V, and Cr. With increasing laser power, the size of the transition zone gradually decreases. Furthermore, the results of composition analysis of transition zone and Mo equivalent calculation show that the direct transformation of α+β→β causes the sudden change of microhardness at the cladding interface when the heat affected zone transfers to the cladding area.