Global contingencies and economic climate risks create uncertainty for firms. To explore the impact of uncertainty on business decisions and investment behavior of firms, this study commences with a theoretical comparative analysis of the impact mechanisms of Economic Policy Uncertainty (EPU), Trade Policy Uncertainty (TPU), Government Policy Risk (GPR), and Climate Policy Uncertainty (CPU) on corporate investment decisions. Subsequently, we empirically test these mechanisms using experiential data from Chinese listed companies from 2013 to 2022. Building on this, a more in-depth analysis is conducted to explore whether different types of uncertainties exhibit significant differences in their impact and dynamic effects on corporate investment decisions across various dimensions, including ownership structures, investment types, and industry sectors. The findings indicate that: (1) All four types of uncertainty dampen business investment, but the degree of dampening varies. (2) EPU and GPR impede fixed and financial asset investments but promote R D investment. TPU increases fixed and financial asset investments but suppresses R D investment, while CPU hinders all three types of corporate investments. (3) The differential impact of TPU and CPU on corporate investments in different industries and with different ownership is greater than that of EPU and GPR; (4) Uncertainties affect corporate investment through financing constraints and external demand, with enterprise growth opportunities mitigating the uncertainty-investment relationship.