With the rapid development of renewable energy especially the introduction of offshore-wind power plan in Guangdong province, to study the capacity of renewable energy integration is very significant because a large scale of renewable energy integrated into Guangdong power grid can severely influence the power grid. The current situation and program of renewable energy are summarized briefly. A calculation method of renewable energy integration capacity based on power balance after renewable energy admitted is proposed by all-round analysis of renewable energy’s output characteristics, load characteristics, ability of powers peak load regulation and comprehensively considering influence of reserve capacity and ability of tie lines regulation. This method is applied into the analysis of Guangdong power gird’s capacity of renewable energy integration in 2020, obtaining that the accommodating capacity is less than the planed. Some suggestions are put forward for the maximum installed capacity of renewable energy according to the analysis of sensitivity of parameters affecting capability of the renewable energy integration. This research result provides reference to powers program, grid frame construction and operation and dispatch.