Objective:To explore scientific method and corresponding formulas for quantitative sensitive questions survey with the sample selected by stratified two-stage cluster sampling. Methods:Stratified two-stage cluster sampling,unrelated question RRT model,sampling theories,properties of mean were used. Results:The formulas of the estimator of the population mean and its variance for sensitive questions on unrelated question RRT model in stratified two-stage cluster sampling were deduced. The survey methods and formulas were employed successfully in a survey of the frequency of cheating in exams among college students at Suzhou University,and the mean of the frequency was 1.034 8. Conclusion:The method and corresponding formulas for sensitive questions on unrelated question RRT model in stratified two-stage cluster sampling were feasible.