NOVELTY - Forming biomass feedstock of 5-hydroxymethyl furfural (5-HMF) and furfural involves taking biomass raw material, adding solvent, solid phosphate catalyst and soluble inorganic salt, forming a reaction system; at 20-400 degrees C under protection of inert gas, conducting dehydration for 0-100 hours to form 5-HMF and furfural product; placing in separating funnel to separate aqueous phase and organic phase, using DNS method for measuring reducing content of sugar in aqueous phase, and using high efficiency liquid phase chromatographic method for measuring content of 5-HMF in organic phase.    USE - For the preparation of biomass feedstock of 5-hydroxymethyl furfural and furfural (claimed) used as important industrial raw material in petroleum industry.    ADVANTAGE - The conversion rate is more than 99%, and yield of 5-HMF is 71.49%, and selectivity is 71.58%. The method achieves high yield of 5-hydroxymethyl furfural and furfural product. The method overcomes following problems associated with the existing technology: catalyst toxicity, easy corrosion of device, expensive, complex preparation, difficult recycling and other drawbacks. The method uses catalyst exhibiting high catalytic activity, having high selectivity, and high efficiency. The catalyst is environment-friendly. The method forms low amount of by-products that are easy to separate and recycled and so on. The method is efficient, low cost, environment friendly, has safe operation, has wide biomass raw material source, is economical, and has good industrial prospect. The method has fast reaction speed, has high conversion rate and selectivity. The conversion rate of the biomass raw material is more than 99%. The HMF product exhibits high selectivity.    DETAILED DESCRIPTION - Preparation of biomass feedstock of 5-hydroxymethyl furfural (5-HMF) and furfural involves taking biomass raw material, adding solvent, solid phosphate catalyst, and soluble inorganic salt in a reactor, forming a reaction system, where mass ration of the biomass raw material with the solvent is 0-1000, mass ratio of catalyst and biomass raw material is 0-100, the mass ratio of the inorganic salt and the biomass raw material is 0-100; at a temperature of 20-400 degrees C under the protection of inert gas, conducting dehydration reaction for 0-100 hours to form 5-hydroxymethyl furfural (5-HMF) and furfural product; placing in separating funnel to separate aqueous phase and organic phase, using DNS method for measuring reducing content of sugar in the aqueous phase, and using high efficiency liquid phase chromatographic method for measuring content of 5-HMF in the organic phase, where conversion rate is more than 99%, and yield of 5-HMF is 71.49%, and selectivity is 71.58%.