A method and a system for determining configuration and evaluation of distributed generation in a distribution network are provided. The method and system include: the index system and the model of each index for evaluating the reliability of distribution network connected with distributed generation are established, according to the network loss of distribution network,the outage cost and the investment cost of the distributed generation are used to establish an economic model of the distribution network to which the distributed generation is connected, and the power supply reliability indexmodel and the economic model are used as a multi-objective programming model of the distribution network to which the distributed generation is connected, and the optimal configuration of the distributed generation in the distribution network is obtained by using a genetic algorithm. The method and system simultaneously optimize the location and the access capacity, and by comparing and analyzingthe power supply reliability and economy of the distribution network without adding the distributed generation and after adding the distributed generation, the optimal configuration of the access distributed generation in the distribution network is determined to improve the power supply reliability and economy of the distribution network.