Based on a flight of aircraft for artificial rainfall enhancement conducted in the transitional zone of the Sichuan Basin and the surrounding mountainous areas on November 28, 2015, the cloud microphysical characteristics such as particle number concentration (N), effective diameter (ED), and liquid water content (LWC) of the three cloud-infall stages (T1—T3) of this non-precipitating stratiform cloud system were analyzed in terms of time scale and vertical direction. The results show that the cloud thickness distribution of this stratiform cloud system is uneven; the flight altitude (H) is 421—4038 m; the environmental temperature (T) is -4.68—12.2 ℃; the LWC is 0—0.148 g·m?3. Small cloud droplets are mainly liquid, while large cloud droplets and precipitation particles are mainly ice crystals; the average N of small cloud droplets, large cloud droplets, and precipitation particles is 1.22×108 m?3, 6.26×102 m?3 and 5.71×102 m?3 respectively, and the average ED is 4.96 μm, 108.99 μm, and 379.28 μm respectively. N and ED are positively correlated. In terms of time scale, T1 has the richest LWC, mainly coming from 2—10 μm small cloud droplets, and three layers including ice clouds, cold clouds, and cold-warm mixed clouds were detected from top to bottom; T2 has a LWC one order of magnitude lower than T1; no large cloud droplets and precipitation particles were detected in the T3 stage. In terms of vertical direction, the 0 °C layer is located around 2370 m; the water-rich zone is between 2100 and 2400 m. In the sub-zero temperature zone, supercooled water and small ice crystal particles undergo accretion growth, while in the positive temperature zone, large and small cloud droplet particles grow through collision and coalescence. However, in the sub-zero zone, the LWC is relatively low and the temperature is relatively high, resulting in a low water-to-ice conversion efficiency. Therefore, the NPIP is not high, and the precipitation particles do not form ground precipitation after falling out of the cloud due to breakage and evaporation during their descent.