To improve the operation economy and security of power system with the integration of large-scale renewable energy sources, the transmission topology optimization is studied to reduce the operation costs and improve the consumption capability of renewable energy with the satisfaction of security operation constraints at the same time. The problem is divided into an economic dispatch problem and an N-1 checking problem, which are solved iteratively. The economic dispatch problem optimizes the transmission topology and generator outputs, while the N-1 checking problem takes the loss of load as objective function, and considers switching back a transmission line that has been switched out as an emergency measure. The two problems are both formulated as two-stage robust optimization models, which are solved by Benders-dual method. Furthermore, some measures are proposed to speed up the solving process, which are suitable for engineering applications. Simulation results on the modified IEEE 39-bus test system demonstrate the applicability and effectiveness of the proposed method.