With the increasing penetration rate of new energy in distribution network, it is urgent to conduct a comprehensive evaluation on the operation flexibility of distribution network. However, most of the discussions on flexibility are focused on the transmission system, and the evaluation scenario is single and lack of discussion on the interruptible load and other flexibility resources.Based on the clustering of flexibility scenarios, a distribution net-work flexibility evaluation method is proposed. Firstly, the nearest neighbor propagation algorithm is used to cluster the typical distribution network operation scenarios. Then, considering the uncertainty of wind power and load output, nonparametric model is used to fit the probability distribution of prediction error. Then, combined with Monte Carlo simulation and distribution network economic dispatch model, a practical calculation method of distribution network flexibility evaluation index is proposed. An actual distribution network data is used to verify the proposed algorithm, and the impact of interruptible load on flexibility evaluation is studied.