The invention provides a method for evaluating variety by crop trait dynamic forming process. The method comprises the following steps of 1, building a crop function structure model; 2, according to the actually measured environment data and the crop growth data, reversely solving relevant parameters of a source base of the crop function structure model, and calibrating the crop function structure model; 3, simulating the dynamic forming process of each measurable trait of different varieties of crops for the same kind of crop according to the built crop function structure model; 4, according to the simulating results, analyzing the dynamic change of each measurable trait of the different varieties of crops, determining the key process formed by the yield variance of different varieties of crops and the factors causing the yield variance of different varieties of crops. The method has the advantages that the guidance is provided for a breeding scientist to select the excellent variety through computer means, the breeding blindness is reduced, and the breeding efficiency is improved.