The invention relates to a verification method in the filed of electricity systems, in particular to a power grid automatic generation control closed loop detection and verification method based on continuous time sequence simulation. The method includes the steps that a power grid AGC main station conducts calculation according to a power grid facture surface, generates an AGC strategy and sends the strategy to a unit AGC substation, the unit AGC substation starts simulating unit output changes after the strategy is received and rectified to be correct, and a load flow simulation module conducts continuous time sequence simulation by taking one second as a period according to the output changes of an AGC unit so as to generate a new power grid facture surface which is used for enabling the power grid AGC main station in the next period to generate a new control strategy. According to the power grid AGC detection and verification method, the simulation period lasts for only one second, the requirement for real-time data collection is completely and even better met, changes of the operation states of a power grid is well simulated in the AGC adjusting process, the closed loop control effect of the power grid AGC can be intuitively embodied, and the method is a plug-and-play detection and verification method and is simple, easy to conduct and effective.