The conventional optimization methods of distribution network usually take economic functions as objectives, to make the opti-mal operation mode meet some secure and reliable constraints. For these methods, the security as well as reliability is considered individually with respect to economy, resulting in one-sidedness. In this paper, the flexible analysis method is introduced to the optimization of distribution network, and the index to evaluate the flexibility of operation is proposed. The objectives and con-straints of the conventional optimal model are made flexible, and then the flexible comprehensive optimal model for distribution network operation is established based on flexible analysis.