In this study, transgenic tobacco with color potato StAN1 gene was used as the material, and the wildtype tobacco (WT) was used as the control. The tolerance of the transgenic StAN1 gene tobacco to drought (mannitol) during the seed germination, shoots and seedling stages, and the tolerance to drought and heat common stress in the seedling stage was measured and analyzed, so as to explore the function of the StAN1 gene of colored potato and provide a new path for droughttolerant colored potato breeding. The results showed: (1) the positive rate of StAN1 transgenic tobacco was 82.6%, the leaves of transgenic tobacco were obviously purple, and the anthocyanin content was significantly higher than that of wildtype tobacco. (2) When the mannitol concentration in the medium was 150 mmol/L, the germination rate of the transgenic tobacco on the medium reached 7% on the 5th day, which was 2.3 times of wildtype tobacco. (3) When cultured vertically on the medium with mannitol concentration of 0 and 100 mmol/L, the root length of transgenic tobacco was 1.46 and 1.30 times of wildtype tobacco, which was significantly longer than that of wildtype tobacco. (4) Under drought stress, the proline content and superoxide dismutase activity in the leaves of transgenic tobacco seedlings were significantly higher than that of wildtype tobacco, and the content of malondialdehyde was significantly lower than that of wildtype tobacco. (5) The relative expression levels of LEA and ERF genes in transgenic tobacco were higher than those in wildtype tobacco under drought and drought heat treatments. Studies have shown that the StAN1 gene not only increased the anthocyanin content of plants, but also improved the drought tolerance of plants.