Mortgage-to-mortgage is the operation mode of reverse mortgage loan, that is, the property owner mortgages the house with his own property rights to financial institutions such as banks and insurance companies. After comprehensively evaluating the borrower's age, life expectancy, present value of the property and the estimated value of the property at the time of the owner's death, the latter will give the owner a fixed sum of money every month, and the owner will continue to obtain the right of residence until the owner's death. When the owner dies and his property is sold, the proceeds will be used to repay the principal and interest of the loan, and the appreciation will also be owned by the mortgagee.