I didn't find out from the RPC document how to judge whether PKH reveals or not. I also try to get status from https://api6.tzscan.io/v3/account_status/ ,but i can't get what i want. So how to use RPC to judge whether a PKH is revealed?
You should ask the manager_key of the account : either it is a key_hash (not revealed) or a public key (revealed).
See this blog for an introduction to the RPCs for a basic wallet :