Abstract: After the Fukushima accident, the accident treatment strategy under extensive damage conditions of nuclear power plant’s related equipment caused by extreme disasters has become one of the issues that nuclear safety must pay attention to. In this paper, considering extensive damage of EPR in Taishan nuclear power plant, the representative scenarios of station black out are selected to perform sensitivity analysis, based on the system characteristics of the nuclear power plant and the configuration of the mobile equipment of nuclear power plant, relevant mitigation action requirements and key time of reactor coolant system water injection strategies for core damage control and mitigation under accident scenarios, so as to effectively mitigate the accident progression. On this foundation, reactor coolant system water injection strategies of EDMGs have been formulated.