NOVELTY - A linezolid preparation method involves utilizing coffee nitro imidazoline that is prepared from 3-fluoro-4-benzene, morpholine and acetone in 0-5 degrees C ice bath by dropping 3, 4 nitrobenzene to rise the temperature. The obtained mixture is stirred with 3-4 morpholine nitrobenzene, (X)2 and hydrogen gas by adding a catalyst under pressure of 80 Pa at 36 degrees C for one hour to obtain coffee 3-4benzene amine. The obtained amine product is added with 3-fluoro-4-morpholine phenyl acetone, water and sodium bicarbonate in an ice bath at 0-5 degrees C.    USE - Method for preparing linezolid.    ADVANTAGE - The method enables preparing the linezolid by improving the purification of intermediate product with high yield rate in an eco-friendly manner.    DETAILED DESCRIPTION - A linezolid preparation method involves utilizing coffee nitro imidazoline that is prepared from 3-fluoro-4-benzene, morpholine and acetone in 0-5 degrees C ice bath by dropping 3, 4 nitrobenzene to rise the temperature. The obtained mixture is stirred with 3-4 morpholine nitrobenzene, (X)2 and hydrogen gas by adding a catalyst under pressure of 80 Pa at 36 degrees C for one hour to obtain coffee 3-4benzene amine. The obtained amine product is added with 3-fluoro-4-morpholine phenyl acetone, water and sodium bicarbonate in an ice bath at 0-5 degrees C by dropping formic acid benzyl ester for reacting with the ice water to separate white solid of coffee N-carbobenzyloxy-3-4-aniline. The resulting aniline compound is added with ammonia water in the ethanol solution and epoxy chloropropane to obtain solid (2s) 3-chloro-2-hydroxy-propyl amine hydrochloride. The resulting substituted amine hydrochloride is added with methylene dichloride and acetic anhydride for heating at 38 degrees C, followed by adding pyridine to obtain an intermediate (2s) 3-chlorine-2-acetoxyacetyl propyl amine. The obtained morpholine derivatives are stirred with and dimethyl formamide solution and methanol for about 30 minutes in a reaction solvent ice bath at 5 degrees C. The reacted product is added with saturated ammonium chloride, water and saturated salt solution for extracting the dichloromethane and separating the water phase from methylene dichloride extract. The extract is concentrated to obtain an oily matter that is crystallized to form linezolid acid in dichloromethane and normal hexane.