Expending 58 typhoon cases that had the considerable effect on Ningbo and had finish catastrophe records from 1949 to 2015. In view of the information of the calamity, the comprehensive correlation degree of typhoon disaster (R_oj) was set up by utilizing the grey relational investigation technique. Choosing the disaster-causing factors of typhoon and R_oj that point build disaster pre-assessment technique of typhoon disaster by utilizing BP neural network (BP). The outcomes demonstrated that, the severity of typhoon which evaluated by R_oj is reasonable and available. There is a significant correlation between typhoon disaster risk factors and disaster assessment indicators as well as R_oj. The pre-evaluation model of BP is useful for predicting typhoon disaster;the correlation coefficient linking the simulated value and the actual value of the training set and the test set respectively reached 0.94 and 0.896 and both achieved the confidence interval of 0.01. The consensus rate of the disaster level forecast of the training set and the test set is 85.3% and 77.8% respectively. This investigate outcomes could provide scientific premise to counter the typhoon work of government decision-making divisions.