global warming has increased the frequency of forest fires and droughts, which have had a number of effects on the hydrologic ecosystems of watersheds`. therefore, the influence of forest fires on forest watersheds and the problem of late restoration are worth studying. the case studies from different regions of the world about how forest fires affect the hydrological process by consuming plant canopy and waste, affecting soil porosity and affecting organic matter of the soil are discussed in this paper. the effects of forest fire on soil permeability and soil water storage are studied by observing soil moisture and matrix potential. a rainfall-runoff model is established to analyze the comprehensive effect of forest fire and climate change on flooding. the results show that forest fires have an obvious regulating effect on watershed. mineralization and deposition of soil organic matter, interruption of vegetation root absorption and loss of crown shade will further affect water quality. additionally climate change will aggravate the erosion of watersheds by forest fires. at the same time, managing forest fires can increase landscape heterogeneity. the study concludes that forest fire is a key factor affecting water resources. at the same time, the impact of forest fires on watersheds varies with the degree of burning. it can be seen that forest fires play a crucial role in guiding the hydrological regulation and restoration of the watershed.