The invention relates to a continuous preparation method for 5-
hydroxymethylfurfural (HMF) transformed by a
biomass saccharine source under
microwave radiation condition by using an
ionic liquid as a reaction medium, in particular to a method for continuously preparing and separating HMF. The method comprises the following concrete steps: mixing the
ionic liquid and
hexose or
hexose source
biomass as a
raw material substrate in a preheating and dissolving
system, preheating and dissolving the mixture, feeding the mixture into a
microwave reaction system to react for 30 seconds to 30 minutes under the
microwave radiation condition so as to efficiently generate the HMF; then feeding the reaction mixture into a depressurizing and distilling
system, and distilling the mixture under the condition that an
operation temperature is not higher than 180 DEG C to obtain the HMF, wherein the separation yield is as high as 94 percent; and re-feeding the distilled remainder into a preheating
system, adding the
biomass saccharine source, and then repeating steps of reaction and separation, so as to achieve the aims of recycling of an
ionic liquid catalyst system and continuous preparation of the HMF. The method has the advantages of no extra-added catalyst, high HMF selectivity, mild operation condition, quick reaction,
reusability of the ionic liquid, low cost, simple process,
environmental protection and
continuous production, provides a new method for industrialized production of the HMF based on the biomass saccharine source, and opens up a new path for preparing common chemicals in a large scale and replacing fuels.