Flexible tax collection and management is an important measure to promote the modernization of tax administration. This paper discusses the spillover effect caused by flexible tax collection and management policies from the perspective of enterprise uncertainty perception. Taking the tax credit rating policy as the natural experiment, a differentdifference model is constructed to test the effect of the policy on the uncertainty perception of enterprises. It is found that flexible tax collection and management can significantly reduce the uncertainty perception of enterprises. The mechanism test shows that the flexible tax collection and management policy can reduce the uncertainty perception of enterprises by exerting “resource effect” and “information effect”. Heterogeneity test at firm level shows that the positive effect of flexible tax collection on firm uncertainty perception is more obvious in nonstateowned enterprises and small and mediumsized enterprises. Regional heterogeneity test shows that the positive effect of flexible tax collection on firm uncertainty perception is more obvious in enterprises with low fintech level, high industry competition and good business environment. The research conclusions not only enrich the research literature on the economic consequences of flexible tax collection and administration and the uncertainty perception of enterprises, but also provide empirical evidence for further deepening the reform of tax collection and administration system.