The invention provides a method and system for performing a security operation by using a security device. The method comprises the following steps: a security chip acquires login information and interacts with a smart card to obtain verification information, and sends the verification information to a login processing terminal through a login terminal, the login processing terminal verifies the login information and the verification information, and executes a login operation, after login success, the security chip sends an image collection instruction to a camera device, receives first collection information sent by the camera device, judges whether the collection information contains human face information, if so, judges whether the human face information is consistent with a user facepicture, if not, executes the security operation, if not, judges whether at least one of the disenabling conditions is satisfied, and if so, executes the security operation; or, the security chip sends the first collection information to the login terminal, the login terminal performs judgment, and executes the security operation according to the judgment result, therefore the business secret of the employee who logs in by using the security device is protected, and the unrelated personnel are prevented from using the security device.