I have solved, upgrading Data Protection from 5.1 to 5.1.20,after registration to vCenter, restart DP,
Then open "https://dp-address/vdp-configure" to modifty the vCener configuration(sucak as:enter the password again), click "save",the DP will restart,and registering to vCenter again, ater that ,the DP appliance will be display in vCenter Web Client.