This application provides a method for secure multi-terminal cooperative working, applied to a network on which a plurality of terminal devices perform cooperative playing and/or cooperative recording, where the plurality of terminal devices include a first terminal device. The method includes: determining, by the first terminal device, a security mechanism; obtaining, by the first terminal device, cooperative working information, where the cooperative working information is information played and/or recorded by the plurality of terminal devices; and performing, by the first terminal device, security processing on the cooperative working information based on the security mechanism. After obtaining the cooperative working information, the first terminal device performs security processing on the cooperative working information based on the security mechanism, so that a process other than the cooperative working process cannot access the cooperative working information, thereby ensuring security of the cooperative working information.