The invention provides an event-based demand response dynamic security service method, comprising the following one or more steps: a security access service step: providing security access service to assess the reliability of an access power consumer, and distributing executable tasks to a power supplier according to an assessment result; a secure communication service step: providing secure communication service to guarantee the communication security between a demand side and a response side; and a security analysis service step: providing security analysis service to determine whether an event is reliable. Under the condition of not influencing the original demand response function and efficiency of an intelligent power grid, the method is provided with an event-based demand response dynamic security service mechanism to enhance demand response security; the method dynamically provides security service for different users through service combination.