Disclosed are a cation polymer, serving as a gene delivery carrier, for removing positive charges by means of an oxidative response, a preparation method, and application. A charge reversal type gene delivery carrier is synthesized from 4-bromomethyl phenylboronic acid and N,N-diethylamino ethyl acrylate by means of quaternary amination. Compared with the prior art, different from a common quaternary amination carrier, the synthesized charge reversal type gene delivery carrier for oxidative response of the present invention has a large quantity of positive charges and can well coat a DNA, but the positive charges can be removed under the condition of intracellular oxidation when the charge reversal type gene delivery carrier enters a cell, a charge reverse is triggered, the positive charges turn to negative charges, and the DNA is quickly released for transfection. The carrier is efficient, low in toxicity, and good in application prospect.
