Applying the traditional Chinese whole view thought and the principles of the modern statistics, meteorology and seismology, it is found that most natural disasters of a sudden (include the extraordinary rainstorm, typhoon sudden change, impending violent earthquake,volcanic eruption, etc. ) are triggered by tide-generating force resonance at collinearity of three stars when the internal conditions are satisfied. Using the internal-external cause coupling method to predict extraordinary rainstorms and impending violent earthquakes, the success rate is respectively about 72.7 % and 40 % . This study program include serie observation experiments to test whether there exist amplifications of the gravitational force and the electromagnetic force at the time of collinearity of three stars and sets up the forecasting mode of extraordinary rainstorm.