The main forms of "fake mortgage" risk are: (1) The developer does not have the qualification of mortgage cooperation subject, or has not signed a mortgage loan business cooperation agreement with commercial banks, without any commitment, and colludes with some lawless people to obtain mortgage loans from commercial banks by false sales. (2) Taking loans for enterprise production and operation in the name of personal housing mortgage loans. (3) Participating in creditor's rights replacement or enterprise restructuring of commercial banks without real and legal transaction basis by means of personal housing loans. (4) Lenders conspire with enterprises to issue a high percentage of personal housing mortgage loans to virtual borrowers or borrowers who do not have real house purchase behavior. (5) All borrowers buy houses falsely, and some of them have unknown identities and addresses. (6) Developers collude with buyers to avoid the policy restriction of not allowing zero down payment.