Dissolved organic matter (DOM) is the most active part of the soil, which is important ecological environment significance. It can provide a basis for soil fertilization management to clarify the impact of different fertilization methods on the chemical properties of DOM. Based on different fertilization methods for four years, this experiment is combined with UV-Visible absorption spectroscopy to explore the changes in dissolved organic matter chemical properties in soil. Four treatments were set up in the experiment: CK (non-fertilization); CF (chemical fertilization); OG (organic fertilization); ST (straw). The results show that, compared with the CK group, the DOC content of OG and ST are 95.97 and 104.89 mg·kg^-1, which are 129% and 141% of the CK group. On the contrary, the DOC content of CF is 15.32 mg·kg^-1, which is 21% of the CK group. OG significantly increase the content of colored dissolved organic matter (CDOM, represented by α(355)), which is 2.76 times that of the CK group, and there is a change in ST inconspicuous; CF significantly reduces the CDOM content, which was only 0.55 times of the CK group. The application of OG caused redshift phenomenon in the ultraviolet absorption curve of soil, indicating the application of OG can increase the conjugated double bond substances and the degree of humification of the soil DOM; Compared with CK, the characteristic constants SUVA₂₅₄, SUVA₂₆₀, and SUVA₂₈₀ of DOM in OG were increased, revealing that the application of organic fertilization could improve the aromaticity, hydrophobic components and humification degree of DOM, the increase in straw treatment was not obvious, but the application of CF showed a significant decrease; The absorbance ratio A₂₅₀/A₃₅₄ was significantly increased compared to CK and CF, indicating that the application of chemical fertilization reduced the DOM molecule, but OG and ST treatments did not change significantly; the application of straw resulted in a significant increase in A₄₆₅/A₆₆₅, indicating that straw could effectively increase the content of protein and carbonhydrate in DOM; A₃₀₀/A₄₀₀ was greater than 3.5 under the application of OG and ST, and it showed this main soil DOM was rich in fulvic acid, while under the application of CF, A₃₀₀/A₄₀₀ was significantly lower than 3.5, showing that the main soil DOM was humic acid. Application of CF showed S_R>1, S_R<1 of CK, OG, and ST which also showed that organic fertilizer and straw could increase molecular weight. In summary, the organic fertilization and straw can effectively increase the soil DOM content and improve soil fertility; especially the application of OG, can increase the conjugated substances, humification degree, hydrophobic ratio, aromaticity and molecular weight of soil DOM. On the contrary, long-term application of CF cause the fertility of the cultivated layer reduced.