Ebullition is a major pathway for methane emissions in freshwater ecosystems such as lakes and reservoirs, characterized by high spatiotemporal heterogeneity that makes it difficult to capture ebullition hotspots. exhibiting high spatiotemporal heterogeneity. In shallow zones near the reservoir tail, sediments tend to produce methane that is released in bubble form. However, capturing CH4 ebullition hotspots in open waters is challenging. During ice cover formation, methane-rich bubbles produced by sediments can become trapped and frozen in the ice, forming visible "ice-trapped bubbles" on the ice surface. This phenomenon allows for the identification of CH4 ebullition hotspots based on the characteristics of ice-trapped bubbles. This study investigates the large Dongfeng Reservoir in northeastern China. Using UAV imagery of the winter reservoir ice surface and field surveys of ice-trapped bubble characteristics, an object-oriented classification method was developed to extract and segment images of ice-trapped bubbles. Spatial autocorrelation analysis was employed to explore the spatial distribution patterns of ice-trapped bubbles and identify hotspot areas of bubble aggregation. The results indicate: (1) The diameter of ice-trapped bubbles in the Dongfeng Reservoir tail ranges from 1 to 10 cm. The spatial resolution of UAV imagery at a flight height of 15 m is 0.4 cm, sufficient for identifying ice-trapped bubbles. The morphological top-hat transformation method effectively improves image illumination uniformity and significantly enhances the quality of orthophoto mosaics.(2) Classification and extraction of ice-trapped bubbles based on differences in aspect ratio, brightness, and density between bubbles and ice cracks show high precision, with overall classification accuracies above 0.8 in the three surveyed bubble zones.(3) The proportion of ice-trapped bubble area among the three zones follows the order R2 > R1 > R3, with the total bubble area accounting for 0.24% of the reservoir tail. However, the bubble area proportions within the ten surveyed transects in the three zones vary between 2.6% and 7.8%. The spatial distribution of ice-trapped bubbles exhibits significant clustering (Moran"s I > 0.8, Z > 80), with "high-high" clusters identified as ebullition hotspots covering 21.5% of the reservoir tail area. Using UAV imagery to identify CH4 ebullition hotspots in ice-covered reservoirs can further guide studies on CH4 emission scales in open waters.