Dear who can help me?
You did not offer how you know the landlord is delinquent in mortgage payments.
The landlord does not lose the right to collect rent until a court intervenes in the landlord and tenant relation, and the tenant is directed by a court order to pay the rent to another.
The practical world suggests that a landlord already in dire straights will not have the mind or energy to go after a rent defaulting tenant.
Read more about your tenant rights at:
The answer provided to you is in the nature of general information. The general proposition being that you should try to avoid a bad outcome if you can.