Abstract: This study utilizes data from the FY-4A/AGRI satellite, Ka-band cloud radar, L-band sounding, and ground-based microwave radiometer to analyze four cases of stratiform clouds with supercooled water at their tops over the Qinling Mountains area of the Danjiangkou catchment zone during winters and springs of 2018–2020. The characteristics of supercooled water in stratiform clouds during winter and spring over the Qinling Mountains area for the four cases are summarized as follows: The height of the 0°C layer ranges from 1 to 2 km, with water vapor concentrations ranging from 1.768 to 2.23 g/m³ and supercooled water contents ranging from 0.014 to 0.325 g/m³. Under the same weather conditions, water vapor concentration is higher than the supercooled water content. The environmental temperature at the cloud tops on the northern and southern sides of the Qinling Mountains is essentially identical, ranging from −17°C to −13.6°C. However, the effective radius of supercooled water particles is smaller over the northern foothills (8.3–13.8 μm) than over the southern foothills (10.5–16 μm). The thickness of stratiform clouds exceeds 2 km, with an inversion layer near the 4–5 km cloud top and a wind direction change at 2 km. On 30 November 2019, at the Jinghe station in the northern foothills of the Qinling Mountains, the characteristics of supercooled water in stratiform clouds were as follows: The ambient temperature range for supercooled water at the cloud top ranged from −17°C to −13.6°C, with an effective particle radius of 9.8–15.3 μm, supercooled water content of 0.2–0.5 g/m³, reflectivity between −20 and −5 dBZ, and water vapor concentration ranging from 1.768 to 2.23 g/m³. Research on the characteristics of supercooled water in the Qinling Mountains has important implications for identifying potential zones for rainfall enhancement in the Danjiangkou Reservoir catchment.