Abstract: Considering the randomness and fuzziness of the failure of piles, the settlement rate of piles is taken as a fuzzy random variable by using related theory of fuzzy mathematics. The membership function is determined by fuzzy statistical analysis of 42 static load tests of prestressed concrete pipe piles in Wuhan area. The probability formula and the calculation method of reliability index are derived by assuming the probability distribution of settlement rate and using the probability theory of fuzzy event. It provides reference for the judgment of failure of piles in engineering practice.