The disclosure relates to a network determining method and device, and belongs to the technical field of a mobile terminal. The method includes the steps of: judging whether a mobile terminal current access network is a set network; and when the mobile terminal current access network is the set network, feeding back a cellular network currently accessed by the mobile terminal to an application of the mobile terminal, the set network being a Wireless Fidelity (WiFi) hotspot network established based on the cellular network. When the mobile terminal current access network is the set network, that the mobile terminal current access network is a cellular network is fed back to the application of the mobile network, and the set network is the WiFi hotspot network established based on the cellular network. When the mobile terminal current access network is the cellular network in essence, that the current access network is the cellular network is fed back to the application, and the application starts using a strategy that the network is used conservatively. Some unessential uploading and downloading operations are avoided, the network usage is reduced, and furthermore the user payment is reduced.