The study of soil soluble organic matter (DOM) and its component leaching characteristics is of great significance in understanding the mechanism of soil carbon and nitrogen nutrient loss under disturbance. Based on the tillage simulation trial, we analyzed the leaching dynamic characteristics of dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and the functional components changes of the DOM in karst calcareous soil and their responses to different tillage frequencies. The main impact of these dynamics was also explored in this study. Our results showed that the leaching amount of DOC and DON increased as the tillage frequency increased, but it did not happen in the four functional group parameters. As the tillage frequency increased, the ratio of DON to total dissolved nitrogen (TDN) increased, but the DOC/DON ratio decreased. The monthly leaching amount of DOC and DON was impacted by tillage treatment, seasonal variation and their interactions. However, the four functional group parameters were only impacted by the seasonal variation. During the experiments, the monthly leaching amount of DOC decreased gradually and the differences among treatments were also reduced, but the leaching amount of DON increased gradually and the differences among treatments increased. The leaching amount of DOC showed a negative relationship with the four functional group parameters, but a positive relationship with the leaching amount of Ca²⁺ and NH₄⁺-N (P < 0.05). The leaching amount of DON had a positive relationship with the leaching amount of Mg²⁺ (P < 0.05), but no significant relationship with the four functional group parameters. We concluded that the tillage increased the leaching amount of DOM, but did not influence the leaching of its stable components, indicating a continuing losses of soil organic matter and a high risk of nitrogen pollution in water would happen if the tillage frequency increase.