Abstract: The relay protection device in the distribution network can effectively improve the reliability of the system,but at the same time increase the cost of the system. The traditional protection distribution method is not suitable for situations involved with distributed power sources. Therefore, an optimization model of distribution network protection distribution considering the influence of distributed power supply is proposed,and the distribution estimation algorithm is used to solve the model. Firstly,the influence of distributed power on the distribution network is analyzed,and then the optimization model of the protection distribution is established,which takes the minimum economic cost as the goal and the reliability of the power supply as the constraint. The optimization model is solved by the distribution estimation algorithm of global optimization. Finally, the simplified topology of an actual substation is taken as an example to verify the proposed method.The results show that the optimization model established in this paper can be well applied to the situation of distributed power access,and the proposed distribution estimation algorithm is superior to other algorithms in convergence for the complex structure of the distribution network.