Abstract: The ways of electrical equipment fault probability influenced by typhoons and rainstorms are analyzed in detail.The scope of data acquisition of blackout defense system is expanded to macroscale meteorological forecast information as well as local meteorological data.A spatial-temporal early-warning method against these natural disasters is proposed.Firstly,according to the information of meteorology,environment,topography and geomorphology,the spatial-temporal evolution trends of typhoons and rainstorms can be predicted and modified.Then,the probability of faults such as broken lines,collapsed towers,flashover caused by adverse weather or derivative disasters such as landslide,debris flow and flood is forecasted on line.Through the module interface between natural disaster evaluation and power system stability analysis,the predictive fault set of online security analysis which was fixed can now be dynamically modified.Therefore,the blackout defense system against typhoon and rainstorm has definite ability of early warning and decision support.