Abstract: The present disclosure relates to titanium alloy powder for selective laser melting (SLM) 3D printing, an SLM titanium alloy and the preparation thereof. The used titanium alloy powder comprises the following element components by weight percentage: 2.0 to 4.5% of Al, and 3.0 to 4.5% of V, with the balance being Ti and inevitable impurities. During preparation, a titanium sponge and an Al—V alloy are mixed and pressed into a block as a melting electrode; the titanium alloy ingot having good uniformity is obtained after smelting by using a vacuum consumable electric arc furnace for three times; and the ingot is forged twice and processed into a bar for powder-making. The bar for powder-making is subjected to processes such as washing and drying, atomizing, sieving, and airflow classification to prepare SLM titanium alloy powder. The titanium alloy powder is melted and stacked layer by layer by means of SLM equipment to finally obtain an SML titanium alloy block.