Effect mechanism of the dissolved organic matter (DOM) extracted from crop straw to adsorption processes of sulfamethoxazole (SMX) on the mineral fine particles was tracked. Under the effect of DOM, the adsorption kinetics of SMX on those particles were compared. The fourier transform infrared spectroscopy (FI-IR) characteristics of mineral particles in processes were analyzed. The adsorption kinetics of SMX on the minerals was well fitted by the two-compartment first order kinetic model, implying that the adsorption processes occurred with the adsorption of the multi-domains or multiple sites. Adsorption quantity of SMX with DOM on montmorillonite, albite and calcite, to a certain extent, had the increase of 28.94, 28.34 and 2.40μg/g. However, the fitting degrees of the two-compartment first order kinetic model were decreased. Base on the FI-IR analysis, the peak values of montmorillonite around 3700, 1600 and 1000cm^-1of the wave numbers and the wide range of 3600~3000cm^-1 were weakened. Moreover, the FI-IR characteristics with the DOM effect were similar. The relatively high capacity was related with the supplemental adsorption sites of montmorillonite because of the interaction between Al³⁺ and DOM. The spectral features of the albite in adsorption processes had slight fluctuation. However, the peak values in the DOM-albite-SMX adsorption system decreased significantly around the 1013, 781 and 460cm^-1 of wave numbers. The phenomenon indicated that the adsorbing capacity of albite increased constantly via the common and/or continuous adsorption. Moreover, the spectral characteristics of calcite in the interaction processes of calcite-SMX and DOM-calcite-SMX were analogous, implying little or no effect of DOM. Nevertheless, the increments in the complex matrices could be related to the combination between DOM and SMX.