The invention discloses a preparation method of an ether high-dispersion high-slump loss resistance polycarboxylate superplasticizer. The preparation method comprises the following steps: (1) conducting esterification reaction; (2) conducting copolymerization; and (3) conducting neutralization reaction. An esterification product comprising carboxyl and multiple ester groups is obtained through theesterification of unsaturated acid anhydride and polyether glycol, the ester group in the molecular group is gradually hydrolyzed under the alkaline condition of a cement paste, and the carboxyl having a water reducing effect is released, so that the slump loss resistance property is improved; the two ends of the prepared esterification product have C=C, the crosslinking point is provided, propercrosslinking is implemented in the copolymerization process, and slight crosslinking helps to improve the dispersion property, the roles of steric hindrance and intercalation resistance are better played, and the ether high-dispersion high-slump loss resistance polycarboxylate superplasticizer is well adapted to the raw materials of sands and stones.