Due to the excellent mechanical properties and excellent biocompatibility, TC4 titanium alloy has been widely used in the aerospace and medical devices field. Laser additive manufacturing (LAM) is an important means of forming and manufacturing titanium alloys. Large numbers of columnar crystals and acicular martensite existed in additive manufacturing TC4 titanium alloy should be addressed, which lead to anisotropy and plasticity reduction of material properties. In this work, molybdenum (Mo) was selected to regulate the microstructure and improve the properties of additive manufacturing TC4 titanium alloy, and the effect of Mo content on the microstructure and properties of laser additive manufacturing TC4 titanium alloy was explored. With the addition of Mo element, TiAl3 phase is gradually precipitated from the alloy matrix, and its content increases with the increase of Mo content. When the Mo content reaches 8wt.%, fine and dispersed lamellar structure is distributed in the alloy, and the β phase content increases sharply, and both the maximum grain refinement degree and dislocation density obtained. With the Mo content increasing from 0 to 10wt.%, the tensile strength, hardness and corrosion resistance of the alloy increase first and then decrease while the elongation follows the opposite trend, the Young"s modulus decreases gradually. When Mo content is 8wt.%, the alloy obtains the best mechanical strength and plasticity, the tensile strength, elongation and Young"s modulus are 1065.6MPa, 11.5% and 55.4GPa, respectively, and the corrosion resistance of the alloy is improved. Overall, TC4-8Mo sample has excellent mechanical properties and good corrosion resistance, and has the potential to be used as human medical implant materials.