A method for a communication device for securely accessing a device includes obtaining accessing authentication information via an out-band channel, the accessing authentication information being used for accessing authentication between a service request device and a service providing device, the service request device and the service providing device sharing the same management device, and forming the out-band channel with the management device respectively (11); and authenticating the accessing authentication information, and providing, by the service providing device, when an authentication result indicates that the authentication of the accessing authentication information is passed, service for the service request device via an in-band data channel, the service providing device and the service request device forming the in-band data channel via a service network (12).