Abstract: In order to effectively strengthen reservoir storage management, delineate the scope for management and protection, it is important to clarify the boundaries of controling area and review the reservoir storage curve, so as to ensure the safe operation of reservoirs and give full play to the benefits of flood control and profit-making. Taking the reservoir storage review of Zaoshi Reservoir as an example, the fast calculation method and accuracy analysis of the reservoir storage and water surface area of large reservoirs were studied. Based on the secondary development of ArcGIS platform, the reservoir storage and water surface area of a specific step length within a certain elevation interval were calculated quickly, and the results were reviewed by using the Global Mapper software and the Yangtze River Hydrological Sediment Analysis Information System. The quantitative analysis in terms of organization and interpolation accuracy of digital elevation model was carried out according to ArcGIS reservoir storage calculation method based on DEM. The results showed that the digital elevation model-based reservoir storage calculation method was fast and can take into full consideration of the changes in the terrain, the irregular ditches and small changes in the terrain can be accurately controlled, which greatly improved the accuracy of the calculation. The maximum discrepancies between this method and the two verification methods were within 1.06% and 1.86%, respectively, and the maximum error in reservoir storage calculation under different water levels would not exceed 1.2%, which can meet the demand for high-precision calculation of large reservoirs.