1,3-dihydroxyacetone was synthesized from paraformalclehyde by the catalysis of 3-ethylbenzothiazolium bromide under the protection of nitrogen with butyl alcohol as the dissovant and triethylamine as the cocatalyst. The effects of react temperature, react time and the amount of triethylamine on the yield of 1,3-dihydroxyacetone were investigated. The preferred synthesis parameters are as follows: the consumption of paraformalclehyde and catalyst is 60mmol and 3mmol respectively, the amount of triethylamine and butyl alcohol is 25mL and 10mL respectively, the react temperature is 130℃,the react time is 40min.The yield of DHA is 37%,the react selectivity is in the 95%-98% range.The purity of the product was increased from 90% to 99.8% after the purification processes of the successive esterification and hydrolysis separation,the total yield of DHA was 72% in the purification.The melting point of the product is 73℃.Its structure was confirmed via analysis of IR、1HNMR and ultraviolet visible spectrum.