With the gradual progress of distribution network reconfiguration, the demand of distribution network customer for power supply reliability is increasing. Therefore, the security performance of distribution network must be enhanced while ensuring its own economic operation. Based on the second order cone programming model and aiming at optimizing the economic performance of distribution network, a bi-level programming model is established by adding the optimization of distribution network security. The objective of upper level is to maximize the average security distance while the lower level is to minimize the active power loss. In order to solve this model, the bi-level model is decoupled by stratified solution. And then, the optimal reconfiguration strategy for guaranteeing power loss and security distance is gained. Simulation results based on the extending IEEE RBTS Bus4 system demonstrate the effectiveness of this model in reducing the power loss and improving the security of distribution network. This work is supported by National Natural Science Foundation of China (No. 51507052).