The alternative iteration method is widely used because of the flexibility of the converter control strategy and the good inheritance of the single-side power flow calculation method. However, there will be multiple alternating iterations between AC and DC systems while the alternative iteration method is used to solve the power flow of the hybrid system based on the existing widely used Voltage Source Converter (VSC) model. To avoid multiple iterative problems and further reduce the computational burden, a new VSC power flow calculation model is reconstructed and proposed. In this model, the active loss of VSC is equivalent to the DC side and the boundary of the AC / DC system is redefined, which can both avoid the multiple alternating iterations problem of the AC / DC system and reduce the power flow computational burden of the hybrid system. Finally, an AC / DC hybrid system is formed by adding DC link in the IEEE9 node system, and is used to test the proposed model. The result validates the effectiveness and efficiency of the proposed model. This work is supported by National Natural Science Foundation of China (No. 51467012).