With the continuous development of active distribution network technology, the flexible load involved in the optimal load scheduling makes active distribution network more flexible scheduling, power grid more secure and reliable operation. In this paper, the flexible load is divided into transferable load and interruptible load，the real-time power of flexible load cells is taken as the control variable to establish a two-tier programming model of active distribution network with flexible load. The upper model takes the minimum grid running cost as a target function in a complete scheduling cycle. The lower model takes the lowest running cost of each micro-grid region as the objective function. The proposed two-level programming model is solved by standard genetic algorithm and simulated annealing algorithm. The case study shows that the introduction of flexible load into the optimal distribution of active distribution network can reduce the system scheduling costs, and the scheduling costs are gradually reduced with the increase of flexible load dispatch.