The present invention relates to a method for access control of a multimedia system to a secure operating system and a mobile terminal for implementing the method. The method includes the steps of: initiating an application access request for selecting a trusted application from a client application of a multimedia system to a secure operating system; making a decision as to whether the client application is a malicious application, and if not, proceeding to a next step, if yes, returning Selection Failure to the client application and performing an interrupt handling; sending the application access request from the multimedia system to the secure system; and acquiring, at the secure operating system, the trusted application based on the application access request and returning the trusted application to the multimedia system. The malicious accesses initiated by a malicious application to a trusted application in a securing operating system can be prevented without switching between systems, and the problem that a trusted application cannot be accessed due to malicious access can be avoided.