The embodiment of the invention discloses a method for acquiring management function information, and a communication system and related devices thereof which are used for enabling a management serverto accurately acquire management function information after being proxied by a proxy device. The method comprises the following steps: an inquiring request sent by the management server is received by the proxy device, and the inquiring request is used for requesting to inquire the management function information after being proxied by the proxy device; and the proxy device feeds back the management function information after being proxied by the proxy device according to the inquiring request. The embodiment of the invention also provides the communication system and the related devices. Theinvention can enable the management server to accurately acquire the management function information after being proxied by the proxy device.