To solve the issue of distribution network operation comprehensive status assessment, the concepts of minimum distribution island and minimum distribution subnet are proposed. Five levels of minimum distribution subnet operation state are given. A detailed analysis of the characteristics of each state is made. Based on minimum distribution subnet, index score of each state in the subnet and the corresponding formula are given. In accordance with the precautionary principle, the running state and index score of the worst distribution subnet are regarded as the entire distribution network operations and index score. Based on improved radar chart analysis, a description of the five state levels of concentric circles drawn is given. In accordance with the current status assessment indicator, 15 minutes status assessment indicator and 60 minutes status assessment indicator, combined with the radar chart area and perimeter, three distribution network status assessment indicators are presented. The characteristics of the three indicators are analyzed with an example. The example analysis shows that the proposed method is feasible. The case research shows that the proposed method can clearly reflect the reaction operating status of the distribution network. It provides a reliable basis for real-time operation of the distribution network, and has good practical significance.