The work aims to study a smart anti-corrosion coating to solve the corrosion problem of Q235 steel. Firstly, the pH-sensitive organic-inorganic hybrid hydrogel of BTA@PHVA/PEI preloaded with the inhibitor benzotriazole was prepared through free radical polymerization method with triethoxyvinylsilane, acrylic acid and hydroxypropyl acrylate as the monomers. The morphology, structure, thermostability and pH-sensitivity of BTA@PHVA/PEI were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric/differential scanning calorimetry analysis and ultraviolet-visible spectroscopy, respectively. Afterwards, a smart anti-corrosion coating was fabricated on Q235 steel by the dispersion of BTA@PHVA/PEI into alkyd resin. The self-healing performance of the smart coating in the corrosion medium of NaCl was investigated via electrochemical impedance spectroscopy and Tafel polarization curve in sequence. The anti-corrosion performance of the smart coating was evaluated by the salt spray tests. Meanwhile, the self-healing mechanism of the smart coating was also discussed. The releasing rate of BTA from BTA@PHVA/PEI rose with the increase of the external environment pH values. The cumulative releasing rate of benzotriazole for 32 h immersion in the solution with the pH values of 2.0, 7.0 and 11.0 was 68.78 wt%, 74.51 wt% and 91.02 wt%, respectively. The optimal content of BTA@PHVA/PEI doped into the smart coating was 10 wt%. The self-healing and anti-corrosion performance of the smart coating based on BTA@PHVA/PEI for Q235 steel are remarkable, which can be also used for corrosion protection of other metallic materials.The self-healing mechanism of the smart coating is that BTA@PHVA/PEI doped into the coating can release benzotriazole molecules response to the corrosion-induced changes of pH values. The released benzotriazole molecules can form an adsorptive film on the steel for preventing the corrosion development.