Abstract: Based on the data of rammed soil-cement pile composite foundation loading tests, the settlement rate of composite foundation is used as an analytical variable considering its randomness and fuzziness of the failure. The membership function of the failure state is obtained by fuzzy statistic method and the parameter distributing of the variable is obtained with the probability statistic method. From the concept of probability theory and fuzzy mathematics, the calculation method of fuzzy random reliability of composite foundation losing its stability have been established and the reliability index of rammed soil-cement pile composite foundation based on load test have been analyzed through examples.