The service performance of Zr alloy cladding can be enhanced by synthesizing a protective coating material on its surface, and also the zirconium-water reaction under steam higher than 1200℃ is delayed, so the accident tolerance of the current nuclear fuel assembly in the event of reactor loss of water is improved. Therefore, the coating technology is also listed as a short-term plan for the design and research of accident-tolerant nuclear reactors. In this study, a plasma enhanced physical vapor deposition technology was employed to prepare Cr coating on the surface of Zr-4 alloy, and ion bombardment and implantation was carried out specifically for the interface between coating and substrate. The properties of the coating system and its influence on the zirconium alloy matrix were evaluated. Compared with the uncoated Zr-4 substrate sample, the diffusion of oxygen into the Zr-4 substrate was obviously hindered and the formation of harmful hydrides was effectively inhibited in high temperature steam accelerated corrosion test by Cr coating. The Cr coated sample did not fall off, and the substrate was not be oxidized in the high temperature thermal shock test greater than 1000℃, but the uncoated substrate was totally oxidized. The tensile and internal pressure blasting tests also showed that the Cr coating exhibited good adhesion to the Zr-4 substrate, with little effect on mechanical properties of Zr-4 substrate. It can be considered that the Cr coating is one of the ideal accident-tolerant coating materials on Zr-4 cladding.