［Objective］To address the corrosion issues faced by marine shore-based equipment in harsh marine climates（high salinity and humidity），a long-term protective coating was developed for such applications.［Methods］ A bio-based polyaspartic ester polyurea coating was prepared usingpolyaspartic ester as the matrix resin，bio-based cardanol as a functional additive，HDI trimer as the curing agent，and fillers such as silica，titanium dioxide，barium sulfate，and zinc phosphate. The polyurea coating was subjected to dynamic thermmechanical analysis，water contact angle measurements，resistance to high-low temperature alternation tests，and salt spray resistance tests. Itsstructure and morphology were characterized using scanning electron microscopy and infraredspectroscopy.［Results］The incorporation of cardanol improved the coating’s flexibility from 5 mm to 4 mm and enhanced its adhesion to 8 MPa. The water contact angle reached 97. 8°. After 2 000 hours ofneutral salt spray and high-low temperature alternation tests，the coating exhibited no blistering， delamination，or cracking，indicating excellent corrosion protection and stability.［Conclusion］The polyaspartic ester polyurea coating exhibits outstanding mechanical and anticorrosive properties. Theincorporation of cardanol improves the flexibility of the coating and enhances its adhesion to metalsubstrates. Additionally，the hydrophobic characteristics of the coating and the increased molecularcrosslinking density further enhance its corrosion resistance performance.