Abstract: The silver nanowires/polyaniline (AgNWs/PANI) nanocomposites were prepared by chemical oxidation polymerization with different AgNWs to aniline mass ratios (1∶5, 1∶15, 1∶25), and then were sprayed on indium tin oxide (ITO) conductive glass to obtain AgNWs/PANI electrochromic films. The layered electrochromic device was assembled by ITO electrodes coated with AgNWs/PANI (AgNWs to aniline mass ratio of 1∶15) and poly (3,4-vinyl dioxythiophene) (PEDOT) electrochromic films. The microstructure and electrochromic properties of the electrochromic films and electrochromic device were studied. The results show that in AgNWs/PANI electrochromic films, a linear core-shell was formed by PANI uniformly coating AgNWs, which increased the specific surface area. When the AgNWs to aniline mass ratio was 1∶5, many AgNWs were exposed. When the mass ratio was 1∶25, the film had fewer exposed AgNWs but the formed conductive path had poor continuity. When the mass ratio was 1∶15, AgNWs was perfectly covered by PANI and the conductive path was continuous and uniform. Compared with those of pure PANI electrochromic film, the peak current density, ion diffusion rate and optical contrast of AgNWs/PANI electrochromic films increased, the charge transfer impedance decreased, and the color chage effect was obvious; the electrochromic performance was improved. The electrochromic performance was the best when the AgNWs to aniline mass ratio was 1∶15. The maximum optical contrast of the electrochromic device was 65.2%, the response time of coloring and fading was only 6.5, 4.9 s, respectively. After 1 000 potentiostatic transitions, the optical contrast retention rate of the device was as high as 97.7%, and the coloring efficiency was as high as 124.6 cm² · C⁻¹.