For most users, it is best to choose LPR floating interest rate for mortgage loan, because LPR has a downward trend in the long run. The fixed interest rate is stipulated by the state, which is not affected by the average social profit rate and the change of capital supply and demand in a certain period of time. The interest rate stipulated in the loan contract remains unchanged throughout the loan period. In the loan business for more than one year, the loan contract often stipulates an interest rate standard agreed by the borrower and the borrower to calculate interest, which is called the loan fixed interest rate. For example, international medium-and long-term export credit calculates interest on the money withdrawn or loan balance during the whole loan period according to the unified interest rate stipulated by the Organization for Economic Cooperation and Development when signing the contract. Floating interest rate loan is a kind of loan, whose interest rate is calculated based on a selected market interest rate at a predetermined time interval during the loan period, and then a certain percentage determined by the bank is added to the basic interest rate, and the interest rate fluctuates with the change of the selected basic interest rate. As the base interest rate, it can be the rediscount rate of the central bank, the treasury bill rate, the interbank offered rate, the subordinated negotiable deposit certificate rate or other financial market interest rates.