With the expansion of the wind farm scale, and the more and more complex topology, collector parameters equivalent has a larger influence on the wind farm modeling. In this paper, the BPA wind farm simulation model and the two machine power grid model are first set up. According to the complex topology wind farm equivalent modeling, an augmented path marking algorithm is proposed to identify the complex topological structure characteristics of large wind farms. Based on the principle of the equivalent modeling of the power loss of the collector parameters, after multiple iterations of the combination of the trunk line and the radial connection, the single computer equivalent modeling of the complex topology wind field is completed. Finally, the dynamic equivalence level of different scale wind farms is simulated by BPA program, and the power and voltage characteristics of the network are compared. It is verified that the equivalent method proposed in this paper can solve the equivalent problem of complex topological wind farms and improve the dynamic equivalence level. For large-scale wind farms to improve the adaptability of network power, but the adaptability to the transient response characteristics is insufficient, multi machine equivalent modeling is still needed.