The tradeoff theory holds that the level of tax burden will be adjusted when it deviates from the target. As an external environmental shock, climate physical risks may not only strengthen firms motivation for tax burden adjustment by raising their operating pressure and prompt management to exercise greater diligence and responsibility in making tax burden adjustment decisions, but also increase the difficulty of tax burden adjustment by exacerbating uncertainties in the firms operations and tax policies. This paper uses Shanghai and Shenzhen Ashare listed firms from 2007 to 2023 to construct the research sample. The test results show that the higher the climate physical risk, the faster the firms adjust to the target level of tax burden, indicating that the climate physical risk has a promoting effect on the adjustment of firms level of tax burden. Mechanism tests reveal that climate physical risks accelerate the adjustment speed by enhancing the motivation for tax adjustment and the effectiveness of tax adjustment decisions. Further research shows that compared with the upward adjustment (increasing to the target value), climate physical risk has a more obvious promoting effect on the downward adjustment of tax burden level (reducing to the target value). The promoting effect of climate physical risk on the adjustment speed is more pronounced in smaller firms, firms with lower agency costs, hightech firms, and firms operating in industries sensitive to climate physical risk. This study not only sheds light on the determinants of corporate tax burden adjustment speed, but also examines the economic consequences of climate physical risk from the perspective of tax management, which is conducive to understanding how climate physical risk affects corporate behavior.