Abstract: As an important inorganic electrochromic material,nickel oxide(NiO)is often used as the anode electrochromic layer of complementary electrochromic devices in smart windows and other fields,due to its great features such as low price and large optical contrasts.The key to the large-scale application of nickel oxide-based electrochromic devices is to improve electrochromic performance and cycle stability of NiO films.Therefore,this paper starts with the electrochromic mechanism and fabrication of NiO film,focuses on the methods to optimize the electrochromic properties of NiO film,then introduces the electrochromic devices based on the anode electrochromic material NiO,discusses the decay mechanisms that limit the practical application of electrochromic devices and presents effective measures to improve the cycle life of devices.Finally,the application prospect and development trends of nickel oxide-based electrochromic devices are summarized.