Microbial degradation is one of critical strategies for the removal of persistent pesticide residues in agricultural soils. However, there is still a great knowledge gap as regards the mechanisms underlying the microbial degradation of nicosulfuron, a typical sulfonylurea herbicide, as well as its related long-term residues and ecological risks. This study was conducted with the aims to explore the influence of two typical soil active components, viz. montmorillonite (MMT) and humic acid (HA) on the biodegradation process of nicosulfuron by an efficient degrading fungus, Talaromyces flavus LZM1. Utilizing the sophisticated analytical methods that include scanning electron microscopy with energy dispersive spectrometer (SEM-EDS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF), we carried out the investigation not only for the influential mechanism of MMT, HA, or their alliance as MMT-HA on biodegradation of nicosulfuron, but also for the changes of degradation products and routes and the regulatory role of different soil active components. The results showed that the soil active components, whether applied individually or in concert, can significantly modify the degradation process by providing either a suitable surface residing environment for microbial colonization or serving as a source of energy metabolism substances. These conditions led to changes in fungal mycelial structures, improvements in microbial cellular activity, and ultimately enhanced biodegradation performance against nicosulfuron. Due to the amendment of soil active components, interestingly, the biodegradation of nicosulfuron were transferred from first-order to zero-order kinetics, which implied the soil active component can not only improve the microorganisms"" adaptability under high pollution stress but also mitigates the soil-phase interfacial mobility and secondary toxicity of key degradation products, e.g. 2-amino-4,6-dimethoxypyrimidine (ADMP). The research further revealed that the soil active components promote the production of antioxidant substances like microbial orsellinic acid, which conversely reduced ADMP accumulation through complex formation. Specifically, MMT was found to notably suppress the generation of hydroxylated product, while HA was indicated to stimulate the formation of alcoholysis derivatives. These obtained results would contribute to a more profound understanding of the microbial degradation mechanisms of nicosulfuron, and provide a scientific guideline for regulating the degradation performance and fostering the practical application of microbial degradation techniques for nicosulfuron in agricultural soils.