Abstract: Iodine-ion thrusters are mainly used for attitude control and position maintenance of small satellites. They rely on the sublimation and ionization of iodine to generate thrust. The heating methods and structural parameters of the iodine feed-ing systems have a significant impact on their own working performance. The dynamic grid method was applied to simulate the sublimation phase-transition process of the iodine in the storage tank to study the effects of heating methods and ratios of diameter to height on the performance of storage tank of an iodine-ion thruster. The results indicate that the contact heating method shows the best performance considering the mass flow rate, flow stability, and preheating time among the three hea-ting methods, such as external heating, radiant heating, and contact heating. Besides, the ratio of diameter to height of a storage tank has almost no effect on the change of flow rate for the contact heating method. The flow stability is good. A lower ratio of diameter to height is better for the iodine-ion thruster designed for high thrust. The mass flow rate at the ratio of 0.2 increased by 9.0% compared to the ratio of 1.4. While a larger ratio of diameter to height is better for the iodine-ion thruster designed for high speed of response. The preheating time at the ratio of 0.2 increased by 80% compared to the ratio of 1.4.