Basically you want to use an image that you used on Construct within your site's CSS file?
In this case the answer is yes. After you have exported the game to HTML5, you will have all the folders/files of your game available. You can then access the folder path where the image you want is located, and use it in any line of code on your site.
Thanks for reply! Yeah, it will work after export to HTML5, but it doesn't work in preview. But it is very inconvenient to build game every time i want to test game with images