Polyaniline (PANI) has good thermal stability and environmental stability, and can be doped with conductive and electrochemical properties and used as a filler in the field of metal corrosion protection due to conductivity and electrochemical property. However, Polyaniline is difficult to be processed and formed due to strong rigidity in molecular chain skeleton and large intermolecular forces. Polyaniline is insoluble in conventional organic solvents and has poor solubility, poor dispersibility, and poor adhesion to metal substrates when used as filler. If reasonably and effectively modified, Polyaniline can solve the above problems. The preparation methods of PANI such as solution polymerization, reverse microemulsion polymerization, template polymerization and electrochemical polymerization were briefly discussed. The problems of PANI in the application of anticorrosion coatings were discussed, and different modification methods such as proton acid doping of PANI and compound modification were highlighted. Chemical modification of PANI by doping with different protonic acids could reduce the interaction between PANI molecular chains, thereby increasing the solubility, conductivity and corrosion resistance. The composite modification of PANI by materials with different properties could improve the intermolecular forces and the processability, and could be applied to the corrosion protection of metals better. Finally, the role of PANI in the corrosion protection process, the application of PANI in anti-corrosion coatings and related research theories are described, and the research emphasis and development direction of PANI anticorrosive coatings are pointed out.