Chitosan-coated mesoporous-microporous composite molecular sieve (CS / MCM-41-A) was used as an adsorbent to remove methylene blue from water. The reaction time, solution pH, initial methylene blue concentration in solution, and CS / MCM-41-A The effects of dosing amount and competitive ions on adsorption were analyzed. The adsorption kinetics and thermodynamic characteristics of CS / MCM-41-A were analyzed. The results showed that when the dosage of CS / MCM-41-A was 0.3 g / L, the initial concentration of methylene blue in the solution was 100 mg / L, the pH was 6 and the adsorption time was 40 min at 25 ℃ Reached 92.57%. The adsorption of methylene blue by CS / MCM-41-A conforms to the quasi-second-order kinetic equation. The adsorption isotherm better conforms to the Langmuir equation. CS / MCM-41-A has good adsorption performance for methylene blue.