Crop dwarf regulator composition

The invention belongs to the agrochemical field and in particular relates to a crop dwarf regulator composition, a preparation method and an application method. Active ingredients of the composition are chlormequat chloride and rare earth element nitrate, and a mass ratio of chlormequat chloride to rare earth element nitrate is 80/1 to 1/80 and is 20/1 to 1/20 preferably. The composition providedby the invention is mainly used for solving the problem that phytotoxicity can be easily caused on crops due to use time of chlormequat chloride and inappropriate usage. The chlormequat chloride and rare earth element nitrate are combined and used, a certain buffering effect is achieved on pharmaceutical effect of chlormequat chloride, the crops absorb chlormequat chloride while rare earth elementnitrate is absorbed, rare earth element nitrate can enable chlorophyll of the crops to be increased, photosynthesis is improved, and disease resistance and stress tolerance of the crops are enhanced,so that the crops have cap