Abstract: The double velocity method based on one-dimensional wave theory was used to test the integrity of pile foundation. The double velocity method was applied to the single pile foundation of communication tower with complex superstructure to determine whether there were defects in the pile foundation. By deducing the principle and applying actual detection test of the double velocity method, it was concluded that the two-speed method could be applied to the detection of the single pile foundation of the single pipe tower, and could accurately determine the pile length and the location of defects, and the interference formed by the superstructure showed insignificant effect on the detection results.