Considering the shortage of the existing reference network models rarely taking the performance of realistic power grid and its operation modes into consideration, an optimization method for reference network considering operation mode optimization and topology correction control is proposed to provide guidance for transmission flexible planning. Based on the forecasted load level in the schedule time scale and candidate branches in network planning strategy, a novel model for reference network is built to minimize the total generation cost and transmission cost, in which the security constraints such as transmission line constraints under normal and N-1 contingency conditions should be respected. The proposed model is a complex mixed-integer nonlinear problem mathematically, and can be converted to a mixed-integer quadratic programming problem, which is solved by the mature mixed-integer quadratic programming method to attain the optimization scheme. Finally, case studies are conducted to illustrate the effectiveness of the proposed method. This work is supported by National Natural Science Foundation of China (No. 51477091) and National Key Basic Research Program of China (973 Program) (No. 2013CB228205).