Abstract: This study takes the detection of internal defects in port pier embankments as an example, and proposes a comprehensive geophysical non-destructive testing method based on the characteristics of different geophysical technologies, including geological radar, high-density electrical method, and seismic imaging method. The research shows that based on the interpretation of data from three shallow geophysical techniques and the use of multiple methods for mutual comparison and verification, the problem of multiple solutions for a single technique can be effectively solved. The types, locations, and scales of internal defects and hidden dangers in the structure can be accurately identified, providing an effective basis for the maintenance, reinforcement, and safety assessment of embankments.