Abstract: The reliability assessment of twoways feeding mechanism is a hard problem，in order to avoid the data fusion problem in reliability evaluation，the Bayes method with inheritance factor which is determined by hypothesis testing was provided. The Bayes with inheritance factor， MML and LM evaluation methods are used to assess the reliability during working process，and the provided method used not only the history data，but also the testing data of system，and the accuracy of calculation improved. Simulation data was used for testing the provided method，the tested results showed that the test data reduces appropriately or the historical data sets increases appropriately， the cost of system testing can reduce effectively， and the efficiency of research improves. Hypothesis testing offers a reference and basis for further reliability evaluation.

Key words: mathematical statistics, feed mechanism, reliability assessment, smallsample, hypothesis testing