With the development of power electronic components, flexible DC technology has gradually been developed. In this paper, a flexible AC-DC converter is added to the traditional AC distribution network to establish an AC-DC hybrid distribution system, and based on the problem of power restoration after short trouble, a semi-definite programming method is applied to realize a fast system power restoration scheme. Firstly, with the structure of VSC model, this paper proposes an equivalent method of VSC converter station based on model parameters, then conducts power flow optimization in AC/DC hybrid system. Then, it uses the algorithm in radial and ring structured hybrid network developed from IEEE 33 nodes respectively, and the calculation and analysis of different equivalent methods are carried out to validate the rationality and high efficiency of the equivalent method. This work is supported by National High-tech R & D Program of China (863 Program) (No. 2015AA050102) and Science and Technology Project of State Grid Zhejiang Electric Power Company (No. 5211JY16000X).