Abstract:The quality inspection of underwater terrain surveying mainly involves setting up a certain number of inspection lines, comparing the water depth difference of measurement points within a certain range at the intersection of the inspection line and the main survey line, and checking parameter information, such as the length of main survey line, the length of the inspection line, the error in each depth interval, and the ratio of discrepancies. The data volume of main survey line and the inspection line is generally large, and relying solely on manual comparison calculation is difficult to achieve efficient and accurate results. At present, Python language has gradually become the mainstream programming language due to its advantages of simplicity, ease of use, and strong scalability; PyQt5 is a widely used GUI toolkit in Python that facilitates the construction of graphical user programs. Poinying to the characteristics of large amount of data and multiple inspection parameters in underwater terrain measurement quality inspection, by using Python language based on PyQt5, a water depth comparison detection system has been designed and developed. It has been applied in the quality inspection of underwater terrain measurement in reservoirs in Shandong province and has achieved good results.