Abstract: To investigate changes in ice thickness, ice temperature, and ice phenology characteristics in Lake Ulansu under the influence of climate warming, the complete process of ice formation and melting of Lake Ulansu from 2015 to 2016 was simulated using the HIGHTSI model. We used the ERA5-Land and MERRA-2 reanalysis data sets for atmospheric forcing, which were combined with initial simulation data obtained from multisource satellite remote sensing images. It was found that: ① During the study period, the maximum ice thickness was up to 41.7 cm, with freeze-up start and break-up end dates of November 21, 2015 and March 25, 2016, respectively, and an ice cover duration of 126 d. ② For Lake Ulansu, which had a shallow water depth and sufficient winter sunshine, air temperature was the main factor affecting ice thickness, followed by solar radiation, and the diurnal cycles of the two significantly affecting the thickness and temperature of the ice layer. However, when the ice was covered with snow, the influence of air temperature and solar radiation on the ice layer was significantly weakened due to the low thermal conductivity and high albedo of snow. ③ Even in the absence of field observation data, the use of meteorological data and initial simulation data derived from remote sensing could still be used to characterize the complete evolution of real snow and ice in the field accurately. This study provided the foundation for the calculation of seasonal ice cover on shallow lake ice in midlatitude arid regions and for investigations of interannual variations in lake ice formation and melting.