The invention discloses a heterogeneous network of wireless service and a switching method thereof. The inside of each network is provided with a node i-Node; the inside of the i-Node comprises a strategy database for storing various communication strategy data, a knowledge database for storing a vertical switching action model counted and formed according to vertical switching action and occupancy rate of a current network channel, a cognition level interface for collecting parameters of each protocol layer, and a cognition platform, wherein the cognition platform is used for judging whetherthe vacancy rate of the current channel is more than a threshold value after a switching signaling of an outer network is received, if so, a connected wireless node accessed to the network is triggered; the wireless node utilizes the parameters of the cognition layer interface and the vertical switching model to implement the switching process, and otherwise, the cognition platform replies a signaling of refusing switching. The invention also provides the method for switching the heterogeneous network of the wireless service. Through the strategy and the model pre-stored in the knowledge database and the strategy database, the heterogeneous network and the switching method can rapidly improve the service switching process among the heterogeneous networks and reduce the time delay of the switching.