Bluetooth module HC-06 reconfigure baud rate

I didn't know the maximum baud rate of PC is 115200 before I used AT command to set the 921600 as a new baud rate through Arduino for my Bluetooth. Now I can't access to the AT mode again to reconfigure the baud rate. Is there any solution that I can fix this problem>?

Use exactly the same code as you used to set it to 921600. I suspect you are trying to configure bluetooth at 921600. The speed used to configure bluetooth is 9600.