Abstract: Distributed generation access to the distribution network has important influence to the power flow, relay protection, network loss, power quality, reliability and power dispatching of power network, while unreasonable access bring bad effects to the safe operation of power system. This paper analyses the different operating conditions and summarizes factors limit of distributed power supply access, puts forward an universal analysis method of distributed power capacity access. It could satisfy the distributed power acceptance ability analysis and calculation during various operation modes of the distribution network, which has strong applicability in the the actual operation and management of power grid.