Abstract: Microplastics （MPs） refer to plastic particles with the diameter less than 5 mm, which can form combined pollution through adsorption and loading pollutants in water, threatening water ecological health. At present, there is a lack of research on the adsorption of microplastics to heavy metal and organic compound pollutants. Polystyrene microplastics （PS-MPs） were used as the target microplastics, PS-MPs adsorption to combined pollution of Cu（II） and tetracycline （TC） in a single and combined system, and the related adsorption mechanism was discussed. The results showed that compared with the single pollution system, the saturated adsorption capacity of Cu（II） in water by PS-MPs in the combined system was reduced, while the saturated adsorption capacity of TC in water by PS-MPs in the combined system was increased. In the combined system, TC interacts with Cu（II） to form a complex TC-Cu, which is conducive to the adsorption of TC by PS-MPs. Cu（II） and TC could also achieve synergistic adsorption with the help of bridging. However, the coexistence of Cu（II） and TC also cause competition between each other and affect the adsorption. The adsorption of Cu（II） and TC in water by PS-MPs is more reasonably described by the quasi-second-order kinetic model, and the adsorption process include boundary layer diffusion and internal diffusion, and the boundary layer diffusion rate is greater than that of internal diffusion. The Langmuir model is move suitable to describe the adsorption of Cu（II） and TC on Ps-MPs in a single system, while the Freundlich model is move suitable in a combined system. pH had significant effect on the adsorption behavior of Cu（Ⅱ） and TC on PS-MPs, but salinity has no obvious effect. Dissolved organic matter （DOM） had no significant effect on the saturated adsorption of Cu（II） on PS-MPs, but it had a significant effect on the saturated adsorption capacity of TC on PS-MPs in the combined system. With the increase of DOM concentration, the saturated adsorption capacity decreased significantly （p<0.05）. The results could supply an implication for the investigation of the effects of microplastics on co-existing pollutants and their potential ecological risks.