Embodiments of the present invention provide a customizable mobile broadband network system and a method for customizing a mobile broadband network. The mobile broadband network system includes a forwarding layer, a control layer, and a capability opening layer. The forwarding capability and the control capability of the mobile broadband network system according to the embodiments of the present invention are decoupled from each other, and the capability opening layer combines a required capability according to the network customization request, so as to manage the corresponding customized-network instance. Therefore, a mobile network can be customized according to a requirement of a user.