Provided is a novel multifunctional cyclodextrin polymer capable of adsorbing the organic pollutants dissolved in water super-fast. A cyclodextrin polymer with a three-dimensional network structure and quaternary ammonium salt functional groups is obtained by mixing and crosslinking a cyclodextrin, a rigid crosslinking agent, a non-rigid crosslinking agent and a quaternary ammonium salt at certain temperature. The polymer is capable of adsorbing the organic pollutants dissolved in water at an ultra-fast rate, and the polymer after adsorption is easily regenerated and can be repeatedly used multiple times without causing a decrease in the adsorption property.