Distribution network reconfiguration is a non-linear combinatorial optimization problem. It is defined as altering the topological structures of the power system by changing the open/closed states of the sectionalizing and tie switches.The aim is to reduce the power loss, and eliminate the overload of the lines, and improve the power quality, and restore the power supply to non-fault area in the distribution network and so on. Combined with distribution networks, The paper proposed an improved ant colony algorithm under the normal operating conditions to solve the distribution network reconfiguration problem. To demonstrate the validity and effectiveness of the proposed method, an example system is studied.The results on IEEE 71-bus distribution networks are also given,which reveal that the proposed method is feasible and effective.