The photochemical processes of dissolved organic matter (DOM) in freshwater aquaculture ponds have significant environmental effects, yet the specific mechanisms remain unknown. This study investigated the photochemical behaviors of DOM in two typical freshwater aquaculture ponds (Eriocheir sinensis pond and Procambarus clarkii pond) in the Taihu Basin under varying light irradiation intensities using spectroscopic and molecular probe techniques. UV absorption and three-dimensional fluorescence spectroscopy were employed to elucidate changes in the properties of DOM components derived from freshwater aquaculture ponds during light exposure, while molecular probe techniques quantified production rates, steady-state concentrations, and quantum yields of photochemically produced reactive intermediates (PPRIs) (³DOM^*, ¹O₂ and ·OH) generated by the photochemical processes of DOM. Results revealed that two humus-like fractions (C1 and C2) as well as one protein-like fraction (C3) could be modeled from DOM in freshwater aquaculture ponds, which exhibited low degrees of humification but distinct characteristics associated with strong autochthonous sources along with terrestrial and endogenous origins. Dissolved organic carbon concentration, eutrophication degree, and intensity of each fluorescent component were higher in Eriocheir sinensis pond compared to Procambarus clarkii pond. Furthermore, properties of DOM components varied under different light irradiance intensities; no significant changes occurred at low intensities, whereas fluorescence intensity, molecular weight, aromaticity, hydrophobicity declined with increasing irradiation time at high intensities. The photodegradation rates of C1, C2, and C3 of DOM from the Eriocheir sinensis pond were 0.014, 0.007 and 0.021 h^-1, respectively, higher than the corresponding components in DOM from Procambarus clarkii pond (0.012, 0.004 and 0.02 h^-1). Notably, the C3 component exhibited a relatively small proportion but displayed stronger photochemical activity. The production potential of PPRIs increased with the increment of light irradiation intensity. Moreover, the production rates of ³DOM^*, ¹O₂, and ·OH were measured as 1.41×10^-8, 1.32×10^-8, 5.52×10^-12 mol/(L·s), respectively, at high light irradiation intensities in the Eriocheir sinensis pond, higher than the corresponding PPRIs production rates for DOM in Procambarus clarkii pond (9.77×10^-9, 6.34×10^-9, 2.50×10^-12 mol/(L·s)). This study provided theoretical support for enriching the mechanisms of DOM environmental behavior in freshwater aquaculture ponds and preventing and controlling organic pollutants in aquaculture ponds.