Abstract: Active asteroids have received lots of attention since they were discovered. 311P/PANSTARRS is one of the most interesting active asteroids in China recently and one of the targets of Tianwen-2. Because of its small size of about 400m, the Yarkovsky effect may have a significantly influence on its long-term dynamics. This paper discussed the changes in the long-term motion of 311P/PANSTARRS caused by the Yarkovsky effect. By assuming different surface compositions, this simulation introduced the semi-major axis drift by propagating orbits of orbital clones, and the effects of other factors such as close encounters, meteoroid impacts and YORP effect on the orbit evolution of 311P/PANSTARRS were also discussed. Additionally, we estimated the time scale for 311P/PANSTARRS to reach its rotation period of splitting limit. The results of the simulations show that the Yarkovsky effect may cause 311P/PANSTARRS to exit from the resonance region faster when compared to a purely gravitational model. 311P/PANSTARRS will leave the current resonance region after roughly 10Myr and have a chance to become a Mars-crossing asteroid through v6 secular resonance due to the diurnal Yarkovsky effect if its surface is covered by a regolith layer. It is concluded that 311P/PANSTARRS is stable at least 10 Myr time scale even if taking the Yarkovsky effect and the YORP effect into account. Furthermore, the YORP effect may not significantly affect the semi-major axis drift of 311P/PANSTARRS.