i have a site and my few author use copy content they simple spin it and post it to my site. because i pay them for each content. my question is. is this harm full for my local teaching platform? google will ban it yes or no help me.
If they're spinning content, it's not good for your readers or for Google. I'd get rid of the whole lot and start from scratch.
Spinning is never beneficial (and spinners aren't writers, though that's another matter). Not only does Google down-rate you for having crap on your site and potentially ban you from AdSense (though it's not in the list of prohibited content unless you infringe copyright, so the ban would be for "insufficient original content" at a guess), your site will suck horribly. Do you really want people to visit your site and have their first thought be "Good grief, what a pile of crap!" and go elsewhere? If you can't afford proper content, consider including a syndicated news feed or similar. Aggregated content does not pretend to be original, accepts the fact that it does nothing for your SEO, but provides interesting articles for your readers. Of course, the price is that they will go off-site to read the full version, but if it brings them back to your site regularly (rather like hitting Google News for the headlines), it's a bonus. Plus, you can automate it completely.
Pay your authors for original content only. There is nothing to be gained from spin content and much to lose, including your readers and the search engines.
Please, everyone, please listen to me: YOU DON'T GET SOMETHING FOR NOTHING!!! All this stuff about spinning and such - you're trying to get the same results as those who actually work and pay. It doesn't work. There's no magic button that you can push. You do reap what you sew, so start working. You do not get something for nothing. Follow that little bit of advice and you'll see true results.
Using spinned content is never a good idea. People will come to your website for a unique experience.