In order to realize the coordination of economy and reliability of distribution network operation, a decision method of operation mode for distribution network based on evolutionary programming algorithm (EPA) is put forward. The minimum energy losses are taken as the objective, and the power distribution reliability, power flow balance, voltage amplitude, current offside, radiation and no-islanding are considered as the constraints during the selection of operation mode. The operation mode of distribution network considering multiple constraints is determined through searching the states of switches by using EPA combined with improved random mutation strategy. The example results indicate that an operation mode of distribution network and sufficient power supply reliability can be determined by the proposed method. The method has important significance to decide the operation plan and to improve the normalization of operation and management.