The work aims to introduce tannic acid (TA) into the waterborne copolymer coating to anchor and improve coating properties by convenient mixing method so as to provide a novel and simple method of anchoring and reinforcing aqueous polymer coatings. TA was mixed into a self-assembled nanoparticle solution of the synthesized zwitterionic polymer by simple dissolution and dispersion method, and was deposited on bare titanium by cathodic electrodeposition to form TA composite coatings. The morphology of the coating was analyzed by SEM and the thickness, roughness, hardness, bond strength and durability of NP-TAx composite coatings were evaluated by ultra-depth microscopy, pencil hardness test, cross-hatch test and immersion method. Finally, the effect of introduced TA on the antifouling performance of zwitterionic-based coating was evaluated by antifouling test. The zwitterionic-based polymer PIDS was successfully synthesized and self-assembled into nanoparticles with a spherical morphology and a particle size of about 184.8 nm. After nanoparticles were with TA, the composite coating was successfully prepared on titanium by cathodic electrophoresis. The different thicknesses and surface microstructures of composite coating could be obtained by adjusting the deposition voltage and time, which indicated that the preparation method was simple and controllable. After the preparation of NP-TAx composite coating, TA improved the film formation of the coating, which made surface structure of composite coating more flat and uniform. The bond strength of coating increased from 2 to 0 level and the hardness increased from HB to 1H. The stability of the coatings was also greatly increased. Subsequent, the results of antifouling test showed that the TA composite coating still had good antifouling effect against proteins and bacteria, which indicated that TA composite deposition would not affect the existing properties of coating. The composite deposition of TA with aqueous nanoparticles for constructing coating can effectively enhance the overall performance of the coating and is considered to be a novel, simple and effective way to anchor and enhance the coating.