Novel synthesis method of florfenicol

The invention provides a synthesis method of florfenicol (I). The method is characterized by comprising the step of asymmetric Henry reaction: carrying out asymmetric Henry reaction on p-methylsulfuryl benzaldehyde (II) and fluoronitroethane (III) in a catalytic liquid to generate (1R,2S)-3-fluoro-1-(4-(methylsulfuryl)phenyl)-2-nitropropane-1-ol (IV). The florfenicol synthesis process does not increase the burden to the environment, and can save the pollutant treatment cost. In the florfenicol synthesis process, the reaction step is simple, thereby greatly lowering the cost. In the florfenicol synthesis process, the used catalyst is accessible, and the yield is higher.