Synthesis method of high-purity low-chroma 4, 4-dihydroxy diphenyl sulfone

The invention discloses a synthesis method of high-purity low-chroma 4, 4 '-dihydroxy diphenyl sulfone, which effectively reduces the reaction reflux temperature by using a mesitylene/xylene mixed solvent, more efficiently separates water, reduces the excessive oxidation of phenol and phenolsulfonic acid into dark quinone oily substances, improves the conversion rate and reduces the chroma of the product. After the reaction, a solvent extraction method is adopted to remove a system solvent, so that the energy consumption is lower, dark quinone oily substances in the product can be taken away at the same time, the chromaticity of the product is further reduced, and the purity of the product is improved; the basic carbonate is added for neutralization reaction after the synthesis reaction is finished, so that the product purity reduction caused by impurities introduced due to corrosion of the neutralization reaction to equipment in the refining stage is avoided, the equipment investment is saved, the cost requi