Abstract: The construction of Xuzhou metro line passes through a bridge with a large buried pile foundation. In order to distinguish its influence on subway tunnel construction, nondestructive detection of the length of bridge pile foundation is required. Prior to the on-site detection, laboratory studies of the simulation experiment were performed according to the actual situation of the acrylic rods by the shock echo method to detect the length, and it was found that the result and the actual length were consistent, which verified that the shock echo method was feasible for bridge pile foundation depth measurement. At the same time, the sensor layout and the relationship between the signal quality for engineering field detection were summarized. After that, the buried depth of bridge pile foundation is measured on site and how to analyze the data is expounded. The results verify the feasibility of shock echo technology applied to the detection of pile foundation length with large buried depth, and show that when the working condition of detection is complex and the traditional detection method loses the working condition, the impact echo method can be used for the detection, which has the advantages of low error, high efficiency and strong adaptability to the working environment.