Electrochromic materials have very important application prospects in the fields of intelligent display and military camouflage. In order to improve the long response time and poor cycling stability of NiO film in alkaline electrolyte, strontium doped nano-sheet NiO electrochromic films were prepared by hydrothermal method. The lattice distortion caused by ion doping and the synergy of micro-nano structure make NiO thin films exhibit excellent electrochromic properties. Strontium ion doping improves the electrochemical characteristics of NiO film, thus improving the electrochromic response time (coloring time is about 4.5 s, bleaching time is about 2.7 s), and improving the coloration efficiency (CE, 85.2 cm₂^C_-1). On the other hand, it provides support for the NiO crystal structure, strengthens the stability of the crystal structure in the electrochromic process, and significantly improves the cycle stability of the film (the cycle number exceeds 10000). The research results of this paper have certain reference and guiding significance to promote the engineering application of electrochromic materials.