Zhenaguo add this line to your BoardConfig.mk: (as suggested by S34Qu4K3)
BOARD_HAS_NO_SELECT_BUTTON := true
It's that simple. If that doesn't work provide me with the following file: /bootable/recovery/default_recovery_ui.c
and I'll make the required modifications for our button mapping.
Without knowing how you bypassed encryption to flash said recovery our efforts won't be at all effective.
Since your able to successfully build a bootable CWM you may as well make the above simple modification.