To solve the problem that the protective coating on the automobile enginecylinder block was easy to be destroyed and peeled off by the ultrasonic-chemical cleaningprocess，a high-performance waterborne one-component dip-coating was developed and itsapplication effect was studied in this paper. The effects of film former，wetting agent，drier and adhesion promoter on the adhesion，water resistance，salt spray resistance and ultrasonic-chemical cleaning resistance of the paint film were discussed. The results showed that thewaterborne acrylic modified epoxy ester resin TH-8180 and the modified waterborne epoxydispersion H-502-42W were selected as the film-forming material according to the mass ratio of 6∶ 4，and the wetting agent BW-104E and HOS 2413 were selected according to the mass ratio of 2∶3. At the same time，5% cobalt-free environmental protection drier OXY-Coat1101 and 1. 5% adhesion promoter MOAP 1880 were added. The prepared waterborne one-componentdip-coatings had good wettability to the engine cylinder，fast drying speed，excellent water resistance，salt spray resistance and the ultrasonic-chemical cleaning resistance.