Currently, the accurate estimation of the maximum snow water equivalent (SWE) in mountainous areas is an important topic. In this study, in order to improve the accuracy and spatial resolution of SWE reconstruction in alpine regions, the Sentinel-2(MSI) and Landsat 8(OLI) satellite data with the spatial resolution of tens of meters are used instead of the Moderate-resolution Imaging Spectroradiometer (MODIS) data so that the pixel mixing problem is avoided. Meanwhile, geostationary satellite-based and topographic-corrected incoming shortwave radiation is used in the restricted degree-day model to improve the accuracy of radiation inputs. The seasonal maximum SWE accumulation of a river basin in the winter season of 2017-2018 is estimated. The spatial and temporal characteristics of SWE at a fine spatial and temporal resolution are then analyzed. And the results of reconstruction model with different input parameters are compared. The results showed that the average maximum SWE of the study area in 2017-2018 was 377.83mm and the accuracy of snow cover, air temperature and the radiation parameters all affects the maximum SWE distribution on magnitude, elevation and aspect. Although the accuracy of other forcing parameters still needs to be improved, the estimation of the local maximum snow water equivalent in mountainous areas benefits from the application of high-resolution Sentinel-2 and Landsat 8 data. The joint usage of high-resolution remote sensing data from different satellites can greatly improve the temporal and spatial resolution of snow cover and the spatial resolution of SWE estimation. This method can provide more accurate and detailed SWE for hydrological models, which is of great significance to hydrology and water resources research.Remote Sens. 2020, 12, 460 2 of 20 interior, the contribution of runoff from mountain snowmelt reaches more than 80% [3,4]. In addition, in the context of the climate transition from warm and dry to warm and wet in northwest China, the hydrological process of rivers in northern Xinjiang has a significant response to climate change and increased snow cover, leading to an earlier flood season and an increase in peak flow. The northern Xinjiang is one of the areas exhibiting frequent snowmelt flood disasters in Xinjiang [5]. Therefore, the assessment of maximum snowpack volumes plays an important role in regional water resource management and flood prevention [6][7][8].The snow water equivalent (SWE), as an important variable in the earth system, reflects the amount of water resources in the form of snow. The SWE is also the main factor influencing river runoff, the regional water resources supply, and flood safety during the snowmelt period. Therefore, accurate acquisition of the snow water equivalent is of great significance for studies on hydrology, meteorology, the water cycle, and global climate change [8,9]. However, accurate estimation of the watershed SWE is the major problem to be solved in the study of mountain hydrology [10]. There are four commonly used methods ...