after you publish it on scirra arcade,then place that game on a website,it will run an ads,how to remove that ads?
Don't use the arcade version on your own site. Publish as HTML5 and use that export for your own site. The arcade copy has ads in it.
Develop games in your browser. Powerful, performant & highly capable.
how to export the game on my own website?
Export as HTML 5, then add the files to a directory on your site. Read the manual or the tutorials all of this is covered in the beginners information.