In order to solve the problem of grid connection and consumption of new energy in a wide area, the flexible DC grid technology has developed rapidly and has developed into a form of DC ring network. The DC ring network has multiple redundant lines, which can better and more flexibly schedule the power transmitted between each power generating unit and the line. Aiming at the characteristics of flexible DC grid, an optimal power flow calculation method based on second-order cone optimization and super-efficiency data envelopment analysis is proposed. Firstly, based on the steady-state model of AC/DC system with VSC-HVDC, a multi-objective optimal power flow mathematical model with AC/DC system net loss and pollutant emission as the objective function is established. Then, the second-order cone and IPOPT (internal point method) are combined to solve the second-order cone-convex optimization problem. Finally, the effective compromise solution, which is with the highest effective approximation degree, can be selected from the Pareto optimal solution which are set by the SE-DEA. Based on the modified IEEE14 and IEEE30 node examples, the effectiveness and accuracy of the proposed method are verified, which can solve the optimal power flow problem of VSC-HVDC AC/DC system.