Insoluble β-cyclodextrin polymers (β-CDP) were prepared by β-cyclodextrin (β-CD) with 2,4-diisocyanatotoluene(TDI) as crosslinking agent, and the obtained polymers presented good hydrophilicity by tuning the amount of TDI. They were characterized by FT-IR spectroscopy, X-ray diffraction and thermogravimetric analysis, and their solubility in different solvents as well as their swelling capacity in water were measured. The results indicated that the polymerization between β-CD and TDI indeed occurred. In addition, the decomposition temperature shifted about 350℃, the solubility of β-CDP was lower than 0.1% in the organic solvents and the swell capacity was only 0.4mL/g. All these results showed the improved thermostability, chemical stability and mechanical strength. The β-CDP also presented highly catalytic activity for aqueous oxidation of cinnamaldehyde with hydrogen peroxide as oxidant. The yield of benzaldehyde reached 48% and the CDP was reusable. These results demonstrate that the polymer not only reserve the inclusion ability of β-CD but also can be used for organic reactions in aqueous media.