Quality detection is an important link to ensure economic and social benefits of the project.The correctness of the detection result relates closely to the normal operation of the project.Single-beam sounder and multi-beam sounding system are the main measurement measures for the engineering quality detection, and the difference between their measurement results will affect detection result.Qualitative and quantitative analyses are carried out to the measurement data before and after construction by the two measurement measures and the detected sectional data of the difference, and the results show that there is not much difference of measurement data between the single-beam and multi-beam before construction.After construction, riprapping increases the underwater terrain's complexity and the difference of measurement data by the two measures.In addition, the angle and route deviation of the single beam increase the detection errors.Based on the research results, we put forward suggestions on improving the accuracy of the single beam detection.