I think you are asking how you find if your site has a bad backlink associated with it?
If you have signed up to Webmaster tools, this should give you a list of backlinks to your site. You can then investigate these manually to see if they look dubious.
Alterntively, ahrefs, openexplorer or majestic will give a view of links to your site that you can also look at.
yes you are right.After checking bad link then how to remove it?