Basing on the study of degradation and adsorption characteristics of quinclorac and cadmium, bacteria EM1 was used as the test strain. The interaction mechanism of quinclorac-Cd²⁺ combined pollution with Enterobacter ludwigii EM1was investigated by using SEM and FTIR analytical techniques. The experimental results showed that the strains could adsorb Cd²⁺ with quinclorac as the sole carbon source. After 7d culture at a temperature of 35℃, pH 6.0, the degradation and adsorption of quinclorac and Cd²⁺ in 50mg/L reached the maximum, which were 30% and 60% respectively. The SEM results showed that in the process of composite repair the morphology of the cells was changed and a large number of extracellular polymeric substances were secreted in the cell surface. Infrared scanning analysis showed that the changes had not taken place in the cell walls under the stress condition. Hydroxy, aminoacyl, carbon-oxygencarbon bond in the sugar ring and the aliphatic compounds were confirmed to be the key functional groups for the strain to biodegrade quinclorac and adsorb Cd²⁺.