Since rural microfinance is a credit which grants loans without collateral and guarantees to farmers, it is considerably important to evaluate and control the household credit risk. Through establishing the evaluation index system and then using catastrophe progression theory, three common types of catastrophe system and the normalization formula, we get the comprehensive evaluation. Finally, we take the empirical test and the result shows that this method is simpler and more objective which can be used by the credit cooperatives to decide whether to authorize the loans.