Method for preparing linezolid

The invention relates to a method for preparing linezolid. The method comprises the following steps: (1) under nitrogen protection, firstly, adding acetamide to methylbenzene, and then adding sodamide, lithium amide or metallic potassium, so as to prepare an acetamide monosodium salt, an acetamide monolithium salt or an acetamide mono potassium salt; and (2) respectively adding R)-N-[3-(3-fluoro-(4-morpholinyl) phenyl)-2-oxo-5-oxazolidinyl] methanol methanesulfonate and the acetamide monosodium salt, the acetamide monolithium salt or the acetamide mono potassium salt prepared in the step (1) to a solvent to stir and react, after reaction is ended, pouring a reaction solution into purified water and separating out a lot of almost white solid, so as to obtain a target product linezolid. The method has the advantages of few reaction steps, low production cost and high yield.