Abstract: Objective The aim is to solve the problems of TC4 titanium alloy for underwater equipment in traditional forging and casting processes, to explore the feasibility of preparing TC4 alloy by laser melting deposition (LMD), providing a basis for material selection of deep-sea equipment. Methods TC4 titanium alloy is fabricated by LMD technology, the microstructural characteristics is analyzed, and its mechanical properties are evaluated using nanoindentation, tensile test and impact test. A comparative analysis are also conducted with conventional rolled TC4. Results The LMD-prepared TC4 alloy exhibits a unique lath-like α' martensite microstructure, which is significantly different from the equiaxed grains of rolled TC4, the content of β phase is extremely low. The LMD-prepared TC4 alloy exhibits a nanoindentation hardness of 6.65 GPa, much higher than 1.54 GPa of rolled TC4, which achieves a tensile strength of 1 059.4 MPa, elongation after fracture of 10.6% and impact toughness of 43 J. Despite being slightly lower than the 59.5 J of the rolled alloy, the impact toughness of LMD-prepared TC4 satisfies the relevant national standards. Conclusion The LMD-prepared TC4 titanium alloy can meet the strict application requirements of deep-sea equipment, and its key mechanical properties are superior to those of traditional materials. This research is of great significance for promoting the technological development of deep-sea equipment.