The invention belongs to the technical field of high molecular materials, and relates to modification of alumite chromatograph resin, in particular to a preparation method for modified poly(ammonia ester-acrylic ester) emulsion of a polyfunctionality micromolecule compound and application thereof. The preparation method for the modified poly(ammonia ester-acrylic ester) emulsion comprises the steps that prepolymerization is performed on macromolecular polyhydric alcohol, isocyanate compounds and acrylic acid or derivatives of the acrylic acid under the catalytic action of organic tin; acrylate end capping agents are added, antalkali is added, dispersing agents and resin modifying agents are dispersed under high-speed stirring, and then the modified poly(ammonia ester-acrylic ester) emulsion of the polyfunctionality micromolecule compound is obtained. The invention further discloses a formula containing modified alumite chromatograph paint of the polyfunctionality micromolecule compound. According to the prepared alumite paint, the alumite chromatograph fogging phenomenon caused by high temperature and humid climate can be avoided; when chromatograph coating is performed, the levelling property is better, and resin curing is more complete.