Abstract: As the representative device of the third-generation flexible AC transmission system (FACTS), interline power flow controller (IPFC) is greatly capable of power flow control. However, the incorporation of IPFC will increase the non-convexity of optimal power flow (OPF), which makes it difficult to solve accurately and rapidly. Aiming at the challenging convexification of the constraints containing phase angle of equivalent voltage source in traditional IPFC model, the equivalent mathematical constraints of IPFC were reconstructed based on the power injection variables. Then, the further convex processing of the proposed IPFC model was realized by the mathematical deformation, approximation and binary expansion, which transformed the OPF model incorporating IPFC, a highly non-convex optimization problem, into mixed integer second-order cone programming (MISOCP) which was easier to solve. Finally, error analysis was completed and MISOCP model was solved by Matlab/Gurobi in simulation example, which showed that the proposed method had the advantage of rapid calculating and high precision, and could significantly reduce the power generation cost. Therefore, it could provide theoretical and technical support for the online optimal regulation of comprehensive FACTS.