A method for dynamically networking among a plurality of devices in a computer network, comprising the steps of: A1. installing a dynamically networking and resource sharing module set on each of the plurality of devices which need to realize dynamically networking and resource sharing, said module set including a network transmission layer module for transmitting and receiving data; a device management layer module for controlling and managing the connection among the plurality of devices; a service management layer module for performing a service management for the device itself and a node, wherein the node is a combination of a plurality of devices and wherein these devices periodically send device announcement messages to the computer network with multicasting; B1. a device among the plurality of devices serves as a node control device of the node and sends a node announcement message of announcing the existence of the node control device with multicasting; C1, being one of: C1a. a device finds the node by monitoring a node announce-ment message, and a device which request to join into the node registers its service information which can be provided to the node control device of the node; or C1b. the node control device configures other devices on the network so that those devices must register to the node control device its service information which can be provided and join into the node; and D1. the device which has joined into the node finds another device that provides a desired service by indexing the node control device, and obtains the desired service from the other device by sending a service calling message to the other device, wherein the node control device is dynamically designated; and wherein said node comprises a global node and a specific node in a broadcasting domain, service entities on all devices in the same broadcasting domain belong to the same global node in default, and a service entity on any one of the devices can create a specific node other than the global node, and one device is active only in one specific node at the same time. A1. installing a dynamically networking and resource sharing module set on each of the plurality of devices which need to realize dynamically networking and resource sharing, said module set including a network transmission layer module for transmitting and receiving data; a device management layer module for controlling and managing the connection among the plurality of devices; a service management layer module for performing a service management for the device itself and a node, wherein the node is a combination of a plurality of devices and wherein these devices periodically send device announcement messages to the computer network with multicasting; B1. a device among the plurality of devices serves as a node control device of the node and sends a node announcement message of announcing the existence of the node control device with multicasting; C1, being one of: C1a. a device finds the node by monitoring a node announce-ment message, and a device which request to join into the node registers its service information which can be provided to the node control device of the node; or C1b. the node control device configures other devices on the network so that those devices must register to the node control device its service information which can be provided and join into the node; and C1a. a device finds the node by monitoring a node announce-ment message, and a device which request to join into the node registers its service information which can be provided to the node control device of the node; or C1b. the node control device configures other devices on the network so that those devices must register to the node control device its service information which can be provided and join into the node; and D1. the device which has joined into the node finds another device that provides a desired service by indexing the node control device, and obtains the desired service from the other device by sending a service calling message to the other device, wherein