Abstract: From different phosphates，such as sodium hexametaphosphate，sodium pyrophosphate and sodium tripolyphosphate，sodium hexametaphosphate was selected as the raw material to prepare sodium monofluorophosphate.The influences of drying time，synthesis temperature，synthesis time and n(F)/n(P)\〗 on the synthetic reaction were investigated by single factor experiment with sodium hexametaphosphate as raw material.The optimal process conditions were confirmed by selective preference of orthogonal test，i.e.drying temperature 475 ℃，drying time 22 min，n(F)/n(P)\〗=1.10，synthesis temperature 760 ℃，synthesis time 22 min.The purity of the product reached 99.86%，conversion rate of raw materials was 99.74%， and product′s concentration of free fluorine was 7.8 mmol/L under the optimal conditions.The study results provide experimental data for the industrial production.