【Objective】This study aimed to investigate the long-term and synergistic effects of Biochar and organic fertilizer on dissolved organic matter (DOM) in paddy soil. 【Method】Several fertilization treatments were tested over five years, including a control (CK), biochar (BC), fertilizer (N), biochar+fertilizer (N+BC), manure+fertilizer (MF, 25% nitrogen replacement), and manure+fertilizer+biochar (MF+BC, 25% nitrogen substitution). The effects of these treatments on soil pH, total nitrogen, available phosphorus, accessible potassium, soil organic carbon (SOC), readily oxidizable organic carbon (ROC), and dissolved organic carbon were examined. The spectral properties and fluorescence components of DOM were characterized using the ultraviolet-visible spectrum (UV-Vis), fluorescence spectrum, and parallel factor analysis. Also, the specific UV absorbance, UV absorption slope rate, fluorescence index, biological index, humification index, and relative amounts of fulvic acid, tryptophan, and humic acid of the DOM were examined. 【Result】The results showed that by utilizing biochar and organic fertilizer, soil acidity could be decreased and rice productivity effectively increased. The MF+BC treatment had the highest rice productivity and soil available phosphorus of all the treatments. Significantly (P＜0.05) favorable correlations between rice yield and DOM""s bioavailability, aromatization, humification, tryptophan concentration, and hydrophilicity were found. The order of the degree of humification and bioavailability increase in DOM was manure > biochar. Furthermore, biochar significantly increased DOM, fulvic acid, and tryptophan components and promoted the conversion of ROC to dysoxidizable-organic carbon, whereas organic fertilizer increased ROC, fulvic acid, tryptophan, and humic acid components. The application of Biochar and organic fertilizer had an interaction effect on the increase of rice production, ROC, DOM, fulvic acid, tryptophan, aromatization, humification, and DOM bioavailability. 【Conclusion】Thus, the combined application of biochar and organic fertilizers increased rice yield while also enhancing the functional diversity of organic carbon and DOM components in paddy soil.