Abstract: In this paper, the complex of siloxanes was used as the modifying agent to form a dense layer of anticorrosion film upon the inner wall surface of steel for natural gas pipeline by direct spraying process. The testing of infra-red spectrometry and contact angle revealed that the inner wall surface of steels which were taken from the field natural gas pipeline was composed of multiform FeOOH, FeCO₃, α-Fe₂O₃ and a trace of Fe₃O₄. After being modified, the steel inner wall surface was coupled with a layer of super-hydrophobic film with alkyl chains towards the surface by the chemical reaction of steel surface and siloxanes. The average contact angle of the super-hydrophobic film was over 160°. The results of corrosions around the modified steel inner surfaces by 5wt% NaCl aqueous solution with different acidities indicated that the formed super-hydrophobic film was dense and stable, and had excellent anticorrosion properties. The complex of siloxanes used here is easily atomized and has a potential in corrosion inhibition or anticorrosion for wet gas transmission pipelines and natural gas pipelines with certain humidity.