The invention discloses a method for preparing spherical 3D printing powder by utilizing plasma. According to the method for preparing the spherical 3D printing powder by utilizing the plasma, multiple procedures including refining, deoxygenization, slag making, slag fishing treatment, ball forming through air blowing, atomization and the like are not required to be used for preparation, and the prepared spherical 3D printing powder is smooth in surface, uniform in distribution, free of pollution, large in loose weight and good in liquidity, and is a relatively excellent form at present; the plasma is utilized to prepare the 3D printing powder, so that simple and rapid preparation of the 3D printing powder is achieved, the process is simple, no dust or pollution exists, and furthermore, the prepared 3D printing powder is spherical in surface, good in liquidity, low in cost and worthy of being widely popularized; and the prepared 3D printing powder is subjected to quenching treatment byusing water, so that the balling probability of the prepared 3D printing powder is greatly improved, and meanwhile, water cooling greatly reduces the preparation cost and improves working efficiencyfor the preparation process, and is especially suitable for large-scale industrial production.