The embodiment of the invention discloses a method and device for guaranteeing terminal safety. A method to ensure terminal security, a secure storage area is provided on the baseband chip of the terminal. The security storage area is used to store data that safeguards the security of the terminal. The baseband chip performs the following steps: obtaining the authentication data from the safe storage area, sending a state query request to the security management service, and the state of the state. The query request carries the authentication data, which is used by the security management server to determine the identity of the terminal, receiving the state response sent by the security management server in accordance with the status of the terminal, and activating the presupposition in the case of the loss state at the terminal in accordance with the state response, according to the state response. The protection strategy. The technical scheme of the embodiment of the invention can solve the problem of failure of the anti-theft function of the terminal when the operating system on the application processor of the terminal is removed or replaced, and improves the security of the terminal.