Abstract: A comprehensive operation optimization method of distribution network is proposed to solve the optimization problem of complex distribution network. Firstly, the operation status of distribution network is obtained by measuring data. When the voltage of distribution network is abnormal or overloaded, the output value and flexible load value of distributed generation are adjusted by the particle swarm optimization algorithm to optimize the operation state of distribution network; whether the distribution network returns to normal is detected; if the operation index of distribution network is not restored to normal, the network topology of distribution network is further reconstructed and optimized. The output value and flexible load value of distributed generation are further adjusted to optimize the operation state of distribution network. Two examples of IEEE 33 bus distribution network and 85 bus distribution network show that the optimization method can reduce the loss of distribution network by 39.9%, and increase the output of distributed generation by 29.4%. The flexible load compensation cost and incentive load cost of distribution network can be reduced by 50% and 14.8%, respectively. This method makes full use of the regulation ability of flexible load and realizes the interaction between supply and demand.