In geological environment, the adsorption behavior of organic pollutants in organo-mineral complexes influences considerably the migration, transformation and end result of organic pollutants. Batch sorption experiments with clay mineral (montmorillonite) and organic matter (humic acid) ratio were designed to adsorb trichloroethylene (TCE) with the purpose of studying the formation and adsorption mechanism of organo-mineral complexes. The results indicate that the interaction between organic and clay mineral improves the interface hydrophobicity of organo-mineral complexes. Meanwhile, the compositions, structures and properties of organic matter in the organo-mineral complexes may change, which can also affect its adsorption behavior. The K_om of adsorbed TCE in the organo-mineral complexes is higher than that of the source humic acid (HA)(0.587 1 L/g), and hardly changes with the increase of the C/M value. TCE initial concentration also has an influence on the Kom value. With C₀=500 μg/L as the boundary, the K_om value increases with the increase of C/M when the concentration is lower than C₀, and it tends to be stable when the concentration is higher than C₀, with the TCE initial concentration having little effect on adsorption behavior.