A method for accessing to devices in security, comprising: 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; 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, wherein the step of obtaining the accessing authentication information via the out-band channel comprises: receiving the accessing authentication information by the service providing device via the out-band channel, the accessing authentication information being generated by the service request device; sending, by the service providing device via the out-band channel, a feedback message indicating that the accessing authentication information has been stored to the service request device, and receiving, via the in-band data channel, the service request sent by the service request device, the service request comprising the accessing authentication information; and the step of authenticating the accessing authentication information comprises: performing, by the service providing device, validity authentication on the received accessing authentication information according to the stored accessing authentication information. 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; 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, wherein the step of obtaining the accessing authentication information via the out-band channel comprises: receiving the accessing authentication information by the service providing device via the out-band channel, the accessing authentication information being generated by the service request device; sending, by the service providing device via the out-band channel, a feedback message indicating that the accessing authentication information has been stored to the service request device, and receiving, via the in-band data channel, the service request sent by the service request device, the service request comprising the accessing authentication information; and the step of authenticating the accessing authentication information comprises: performing, by the service providing device, validity authentication on the received accessing authentication information according to the stored accessing authentication information.