Hello Li Feng,
From the error message "MCU is unsupported" , it seems your device is not supported by OpenOCD, as OpenOCD needs to be implemented for your microcontroller. Have you tried P&E and Segger debug firmware on the board
already ? I recommend you test Segger debug firmware, the steps are as below :
1)Press the Reset button (and keep it pressed) while power the board withthe OpenSDA USB connector:.
2) The board will show up as BOOTLOADER drive on your system:
3) Copy"29_OpenSDA_TWR-KE18F.bin" to the BOOTLOADER driver:
4) The copy operation takes about 2-3 seconds, after finished , unpower the board.
5) Power the board again normally
Select the "GDB SEGGER J-Link debug" do download and debug :

Have a great day,
TIC
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