Phosphorized polyaniline(P-PANI) was synthesized by using the chemical oxide method with phytic acid(PhA) as a dopant, and after mixed with silicon resin(SiR), it was applied to the surface of magnesium-lithium(Mg-Li) alloy to prepare P-PANI/SiR composite anticorrosion coatings. The structure of P-PANI was characterized by Fourier transform infrared spectrum(FTIR), ultraviolet-visible-near infrared spectrum(UV-Vis-NIR) and X-ray photoelectron spectroscopy(XPS). The influence of different content of P-PANI in composite coatings on the hydrophobicity, adhension and anticorrosion performance of the composite coatings were investigated. The results show that the composite coating has better hydrophobic property and anticorrosion performance when the mass fraction of P-PANI in SiR is 2.0%. The water contact angle(CA) of the coating is 125.4°, the dry and wet adhesion are both 0 grade. The corrosion current density is 5.15×10-10 A/cm2, and the electrochemical impedance values reaches 108 Ω•cm2.