Do you mean the profile page here on Digital Point? Well.. It wont hurt your website's rank, but it wont help much either..
i add my website on profile page of a forum and google have indexed that if i make that on many website for google its spam?
I think google will not see much your site, since it's your profile and it is private page just for you, bots will not crawl them. Why not use the usual yet effective methods on link building?
Don't worry. Google will not penalize you for this. You can always place a link to your website in your profile and/or signature.
If you mean you profile pages here in DP, then it wont help your ranking is it's a 'nofollow' links for both the text link and the snapshot image of the website. But doing so will not hurt your website, at least you might get some new visitors by doing so