The invention discloses a method for preparing 5-methoxy-4,6-dihydroxy 
pyrimidine disodium. The method comprises the following steps: 1) performing Clancy reaction, namely, feeding 
solid sodium ethoxide into a reaction kettle, further feeding 
methoxyacetic acid methyl acetate and 
diethyl oxalate for reaction, after the reaction, adding trichloro 
ethylene, stirring and diluting, adding water, 30% 
hydrochloric acid, adjusting the pH value, separating trichloro 
ethylene, extracting a 
water layer by using trichloro 
ethylene, recycling a trichloro ethylene 
solvent, decarbonizing, and then performing reduced pressure 
distillation to obtain methoxy-
malonic acid methyl 
ethyl ester; and 2) performing cyclization reaction, namely, firstly, feeding 
sodium methylate into a reaction pot, adding a 
silicon dioxide-aluminum 
oxide catalyst, stirring and heating, adding 
formamide and methoxy-
malonic acid methyl 
ethyl ester, after that, keeping the temperature to react, after keeping the temperature, recycling 
methanol till no liquid is discharged, subsequently adding water, cooling, discharging, and rotating a damp product to dry under reduced pressure so as to obtain the 5-methoxy-4,6-dihydroxy 
pyrimidine disodium. The method disclosed by the invention is high in yield, can greatly reduce 
energy consumption, and is applicable to industrial production.