To avoid the flood secondary disasters caused by the earthquake,the department which has the task of flood forecasting set up emergency flood forecasting scheme to provide scientific basis for earthquake relief in earthquake-prone areas.A method of forecasting emergency flood in earthquake areas is provided in the paper.The logistic equations of each kind of emergency rainfall station and area rainfall are set up by dividing the basic classes in the method.The computation method of acquiring time-area rainfall is also deduced.Combined with the available experience forecasting project,the method could implement flood forecasting to satisfy the earthquake relief in earthquake areas.The method does not depend on the rainfall information in all rainfall stations and could solve the problems of lacking of observation data in disaster areas effectively.The application example shows the forecasting result of the method is satisfactory.