The invention relates to a DMP neutralizing treatment method. According to the invention, a reaction tower residue liquid of propylene glycol monomethyl ether is used as a raw material for neutralizing treatment, the reaction tower residue liquid is pumped into a neutralizing kettle; a mixed solid acid is added as a neutralizer to neutralize the reaction tower residue liquid to neutral; stirring and filtering are performed after neutralization to remove salts; the salts obtained by filtering is recycled, and the filtered reaction tower residue liquid is fed into a rectifying system to be rectified. Further, the mixed solid acid is obtained through reaction of a mixed inorganic acid and a neutral curing agent. The method provided by the invention has the advantages that the treatment method provided by the invention can be used for purifying the byproduct reaction tower residue liquid during production of propylene glycol monomethyl ether, the residue liquid is neutralized by the mixed solid acid, and sodium methoxide in the reaction tower residue liquid is removed through filtering so as to obtain environmental-friendly solvents such as dipropylene glycol methyl ether and the like, so that the utilization ratio of the reaction tower residue liquid is improved, and safe and clean production is realized.