Abstract: A technology for the treatment of super-long broken piles and the acoustic principle of ultrasonic method applied to detect the quality of concrete of piles were introduced.The special curve of sonic speed-strength was derived by regression analysis for the adjudgement of concrete strength.The ultrasonic method was employed to monitor the quality during the whole process of treatment of super-long broken piles: determination of the precise location and position before casting;detection and assessment of treatment effects after casting and pointing out the necessity and position of supplementary casting;redetection and reassessment of the effects of supplementary casting.The casting effects and the successful treatment of the pile are ensured through the proposed method.