Is it genuine or he has cheated?Im doubtful as his accuracy is very high..


If you think another member used disallowed resources you should report them, but accuracy as used by the site isn't a cheat detection tool.
https://support.chess.com/en/articles/8562517-how-do-i-report-someone
That said, discussions of cheating, potential cheating, or cheat detection are not allowed in the general forums.