With the rapid development of real estate market and capital market, real estate finance is also developing rapidly. Some residents turn to real estate investment after meeting their immediate housing needs, which stimulates the real estate market and makes the supply and demand of real estate unbalanced, and real estate financial risks also increase. This paper intends to build a real estate financial risk early-warning index system based on the theory of supply and demand and uses the efficiency coefficient method to calculate the comprehensive early-warning value from 2000 to 2020 by taking Chongqing as an example. The results show that the constructed early-warning index has a good early-warning ability, and the real estate financial risk in Chongqing is below the warning value in 2013. In recent three years, the real estate financial risk in Chongqing tends to increase significantly, and there are certain potential risks, which should be paid attention to. To prevent real estate financial risks and maintain financial stability, the joint efforts of many parties are needed: the government should strengthen the supervision of the real estate industry and guide effective investment in the industry; real estate enterprises should deleverage and reduce liabilities and explore new modes of investment development; households should make long-term housing purchase plans and strengthen the awareness of diversified investment; financial institutions should orderly carry out real estate development loan projects and strengthen the credit assessment and management of real estate enterprises.