This article reported adsorption mechanism of mixed pesticides Prometryne-Acetochlor (PA) in soil. Thermodynamics and adsorption isotherms were used to preliminarily evaluate adsorption force, and IR and XRD were used to characterize adsorption characteristics between Prometryne/Acetochlor (PA) and soil, The result shows that adsorption isotherms is F-type, adsorptive heat are 9.57 kJ/mol and -93.83 kJ/mol of prometryne and acetochlor respectively. Hydrogen bonds also had been confirmed by IR and XRD analysis. The results can provide a theoretical support to the use of mixed pesticides agents.