In order to improve the anti-corrosion ability of the photocurable coating，a series of polydecalactone diols with hydrophobic side chains were synthesized from δ -decalactone（DL）， and then urethane acrylate with side chain structure was prepared with isophorone diisocyanate（IPDI） and hydroxyethyl acrylate（HEA）， which were used to construct photocurable metal coating. The structure of polydecalactone diols was characterizedby Fourier transform infrared spectroscopy（FT-IR） and ¹H NMR. The effects of chemical structure and molecular weight on the hydrophobic and anti-corrosion properties of thecoatings were studied. The results showed that the water absorption of hydrophobic side chainmodified polyurethane acrylate coating in water for 400 h decreased from 3% to 1. 4%. In addition，the impedance modulus of the coating soaked in salt water for 400 h increased from 2. 7×10⁷ Ω ·cm² to 1. 1×10⁹ Ω ·cm². The hydrophobic side chain modified polyurethaneacrylate coating showed only slight pitting phenomenon in the salt spray environment for400 h，indicating that the coating constructed by the hydrophobic side chain modified polyurethane acrylate has higher water resistance and corrosion resistance.