Pyrimidine alcohol and potassium carbonate aqueous solution were reacted in organic solvent to dehydrate under reduced pressure,resulting in the condensation reaction of pyrimidinol potassium salt with methyl chloride,and methyl pyrimidinophos was obtained by filtration and concentration under reduced pressure.The optimised conditions were as follows:toluene as solvent,n(pyrimidinol)∶n(potassium carbonate)=1.0∶2.0,water content of pyrimidinol potassium salt<0.1%,reaction temperature 30~40 ℃,reaction time 6 h.The content of the product under the optimised conditions was 98.5%and the yield was 92.6%.The process has high conversion rate,high yield and less waste.In line with green environmental protection production concept,it has the prospect of industrial production.