Abstract: With a large number of distributed power sources connected to the distribution network, it will have a certain impact on the system relay protection, the distribution network from a single power supply, radiation power supply network to a multi-power coexistence system network, the system fault situation becomes complex, affecting the reliability, selectivity, rapidity and sensitivity of the original protection, may cause protection, reclosing and standby self-investment device rejection and misoperation. This paper studies the impact of distributed power access to distribution network on protection, and proposes the configuration and tuning of relay protection for distributed power access to distribution network, so as to accumulate experience for power grid design and operation.