Abstract: With the rapid development of social economy, the frequency of various large-scale and important events is also getting higher and higher. In order to host events more smoothly, the need of society for artificial precipitation suppression technologies during major events is also urgent. Hygroscopic seeding is an important way to suppress precipitation artificially. Although previous research on artificial precipitation suppression basically confirms that the hygroscopic nuclei of smaller than 1 μm can inhibit the convective cloud precipitation, how to use it more effectively to achieve the best effect is still a difficult problem in precipitation research. In order to provide some useful theoretical references for artificial precipitation suppression operations, a two-dimensional slab-symmetric detailed spectral bin microphysical model of Tel Aviv University in Israel is used to simulate the warm shallow convective cloud and precipitation in East China at about 1600 BT on 4 September 2016. The height of the strong radar reflectivity center and the range of high radar reflectivity are basically consistent with observations. The cloud seeding experiments with hygroscopic nuclei smaller than 1 μm are conducted in order to examine sensitivities of seeding effects to seeding time, seeding height and seeding amounts of particles, respectively. Results show that the early seeding in the cloud development stage can lead to more significant effect on rainfall suppression. The earlier the seeding time is, the stronger the inhibition of the growth of large particles. As the seeding time goes backwards, the particle size segment with the most significant inhibition shifts to smaller particle size; the effect of rainfall suppression is more obvious when seeding is carried out just below the area with large supersaturation in the center of cloud. Since a large number of hygroscopic nuclei seeded here enter the supersaturation zone, they are activated to be small cloud droplets, and the cloud water conversion and collision process are suppressed. The reduction rate of ground accumulated precipitation reaches 23.3% when the seeding concentration is 350 cm^-3. In addition, with the increase of seeding amounts of hygroscopic nuclei, the precipitation suppression effect is more significant, and the rain is even eliminated. Therefore, seeding hygroscopic nuclei smaller than 1 μm properly in warm shallow convective clouds can achieve expected results of reducing or eliminating rain.