The fixed line at home received an inexplicable phone call saying that someone had stolen my personal information and borrowed money from the Bank of China. Is it a scam?

This is definitely a scam. If you are cheated, they will ask you to transfer the money in your account to their safe account and show that it is the safe account of the public security organ. Of course, if you transfer money, you are sending them money.

If the bank doesn't pay back the money, even if it is a notice from the bank, how can the postal staff know the content?

Of course, you can also call this bank to check, but be careful, change the phone to consult the bank, because they can pick up your phone line outside the community, and they will answer whatever you call.