Abstract: Water depth determination based on remote sensing data is of great significance to accelerate the collection of basic hydrological data in Hainan Province and simplify the dynamic monitoring of hydrological data in the entire water area. In the report， the data from the Landsat-8 OLI image and the measurement were used and the single-band algorithm， the multi-band ratio algorithm， and the bottom albedo-independent bathymetry algorithm （B algorithm） were performed， and B algorithm was selected as the fittest algorithm for the water depth determination. Aimed at the problem that B algorithm are not accurate when water depth is less than 10 m and over 30 m， the water depth determination model with divisions was proposed and applied. The results indicated that the accuracy of the modified B algorithm is obviously improved， the average absolute error decrease by 45.7%，the relative error decrease by 42.3%. the modified B algorithm model is more fit for the actual water depth distribution of Niululing reservoir， and which can be used to acquire the water depth data of the entire reservoir.