The invention discloses a multihole titanium-magnesium alloy artificial bone capable of promoting bone growth and a preparation method thereof. The artificial bone is prepared from titanium-magnesiumalloy powder. The titanium-magnesium alloy powder is prepared from the following components (in percentage by weight): 0.3 to 9.5 percent of molybdenum, 1.5 to 6.5 percent of nickel, 2.5 to 14.5 percent of cobalt, 1.5 to 3.5 percent of yttrium, 1.5 to 5.5 percent of niobium, 2 to 3.0 percent of magnesium and the balance of titanium and unavoidable impurities, wherein the total percentage of all the components is 100 percent. Compared with the prior art, the multihole titanium-magnesium alloy artificial bone has the advantages that due to the addition of a molybdenum element, the intensity of the artificial bone is enhanced, and the low-temperature characteristic of the artificial bone is improved; meanwhile, according to an improved formula and an improved process, the density, the elasticity modulus, the compressive yield strength and the fracture toughness of the titanium-magnesium alloy artificial bone are closer to corresponding values of a human bone; furthermore, the artificial bone can achieve a mechanical property matched with a bone tissue by adjusting the porosity, so that a stress shielding phenomenon between the titanium-magnesium alloy artificial bone and the bone tissue is relieved.