Abstract: In order to identify the small damage of serving structural pile in high prelision, according to the structural vibration equation of damaged pile, a structural damage identification equation was established which contained modal damage sensitivity factor, the element damage factor and element modal strain energy.Efficient damage identification modals were selected by applying modal damage sensitivity factor.Accurate damage location identification method was established for pile small damage by using efficient damage identification modals and wavelet analysis techniques.On the basis of the damage location identification, the injury severity could be identified by using structural damage identification equation.Numerical simulation of the SF-1 lighthouse pile foundation damage identification was done by applying the proposed method, the result of errors of identification were less than 5% which verified that the proposed method had higher recognition accuracy.The pile foundation damage in the BHX-12 platform was detected by applying the proposed method, the consistent of identification result and actual result proved the practicality of the method.