Abstract:With the depletion of traditional fossil energy, the demand for new energy is very urgent.Distributed power (DG) based on new energy and renewable energy can not only be an important supplement to the traditional power supply mode, but also occupy an important position in the comprehensive utilization of energy.It is in line with the national energy strategy to develop vigorously new energy with distributed utilization. However, with the increasing proportion of DG in power system, it challenges the safety and stability of traditional power system.In order to study the influence of distributed power supply grid-connected on distribution network and improvement measures, the concept, classification and characteristics of distributed power supply are introduced in this paper.The influence of DG grid-connected network on distribution network and the research status of improvement are discussed.After the distributed power supply is connected to the network, the effects of DG grid-connected network on the distribution network and its improvement measures are summarized in terms of distribution network planning, power quality and relay protection.The islanding problem after the fault of the distribution network containing DG and the related research of the microgrid are discussed.The future research direction of DG in the high proportion of power grid development is prospected.