A field experiment was conducted to investigate the effects of reductive soil disinfestation (RSD) and biochar (BC) application on dissolved organic matter (DOM) in degraded vegetable soils. In this study, six treatments, i.e., (1)soil untreated (CK), (2) soil incorporated with 1% (w/w) biochar (BC), (3) soil flooded (SF), (4) soil flooded and covered with plastic film (SFF), (5) soil incorporated with 1% (w/w) alfalfa residue, flooded and covered with plastic film (RSD), and (6) soil incorporated with 1% (w/w) alfalfa residue and 1% (w/w) biochar, flooded and covered with plastic film (RSD+BC) were performed to compare the effects of different treatments on DOM content and its spectral characteristics in soil 0-20 cm and 20-40 cm of layers. The results showed that for 0-20 cm soil, compared with CK, soil pH value of other treatments was increased significantly, and NO₃^--N contents of BC, SF, SFF, and RSD treatments were significantly decreased by 31.9%, 59.4%, 40.0%, and 22.3%, respectively. Soil dissolved organic nitrogen (DON) content was significantly increased by RSD treatment (P<0.05). The contents of dissolved organic carbon (DOC) in RSD and RSD+BC treatments were significantly increased by 188.2% and 201.4% (P<0.05), respectively, whereas the degree of DOM aromatization and humification was decreased under the two treatments. Soil DOM was mainly composed of fulvic acid-like and humic acid-like material, and the fluorescence intensity of DOM in RSD+BC treatment reached the maximum. For 20-40 cm soil, the fluorescence intensity and DOC contents of all treatments were decreased significantly compared with that of 0-20 cm soil. However, compared with CK, the DOC contents in RSD and RSD+BC treatments were still increased significantly (P<0.05), while the DON contents in BC and RSD+BC treatments were decreased. These results implied that the combination of biochar and RSD could further alleviate soil acidification in the short period, improve soil DOC content, and reduce the degree of soil DOM aromatization and humification. This study provides scientific guidance for the remediation and environmental risk assessment of degraded facility vegetable soil.