The invention relates to the technical field of wind power plant equivalence modeling, in particular to a double-fed unit wind power plant dynamic equivalence modeling system and method based on simplified models. Compared with the prior art, the double-fed unit wind power plant dynamic equivalence modeling system and method have the advantages that the converter model in a double-fed wind power generation system is simplified, and the calculation time consumption is greatly lowered. The unit distribution area based on the homology method is used as a grouping index, and applicability to equivalence modeling of wind power plants in different terrains is achieved; parameters, calculated through a capacity weighting method, of equivalence units are wind power plant equivalence, suitable for double-fed units of various types, of the equivalence method. Equivalence is conducted on wind turbines according to the principle of capture wind energy equivalence, and visibility is better achieved.