A switching method for network interfaces, applicable to an access device containing at least two network interfaces, the method comprising: detecting connected states of the at least two network interfaces so as to determine valid network interfaces; and when it is determined that priority of a currently accessed valid network interface is lower than priority of other valid network interfaces, performing network interface switching according to a preset switching policy, wherein the preset switching policy comprises: taking a highest-priority network interface in the other valid network interfaces as a network interface to be switched; characterized in that, taking the highest-priority network interface in the other valid network interfaces as the network interface to be switched comprises: when a bandwidth supported by the currently accessed valid network interface is lower than a bandwidth needed by a current service, taking a highest-priority network interface, which supports a bandwidth higher than the bandwidth needed by the current service, in the other valid network interfaces as the network interface to be switched; or, when bandwidths supported by valid network interfaces are all higher than a bandwidth needed by a current service, taking an interface, which supports a network with a lowest rate standard, in the valid network interfaces as the network interface to be switched; or, when bandwidths supported by the valid network interfaces are all higher than a bandwidth needed by a current service and rate standards of networks supported by the valid network interfaces are the same, taking an interface, which supports a highest bandwidth, in the valid network interfaces as the network interface to be switched. detecting connected states of the at least two network interfaces so as to determine valid network interfaces; and when it is determined that priority of a currently accessed valid network interface is lower than priority of other valid network interfaces, performing network interface switching according to a preset switching policy, wherein the preset switching policy comprises: taking a highest-priority network interface in the other valid network interfaces as a network interface to be switched; characterized in that, taking the highest-priority network interface in the other valid network interfaces as the network interface to be switched comprises: when a bandwidth supported by the currently accessed valid network interface is lower than a bandwidth needed by a current service, taking a highest-priority network interface, which supports a bandwidth higher than the bandwidth needed by the current service, in the other valid network interfaces as the network interface to be switched; or, when bandwidths supported by valid network interfaces are all higher than a bandwidth needed by a current service, taking an interface, which supports a network with a lowest rate standard, in the valid network interfaces as the network interface to be switched; or, when bandwidths supported by the valid network interfaces are all higher than a bandwidth needed by a current service and rate standards of networks supported by the valid network interfaces are the same, taking an interface, which supports a highest bandwidth, in the valid network interfaces as the network interface to be switched. when a bandwidth supported by the currently accessed valid network interface is lower than a bandwidth needed by a current service, taking a highest-priority network interface, which supports a bandwidth higher than the bandwidth needed by the current service, in the other valid network interfaces as the network interface to be switched; or, when bandwidths supported by valid network interfaces are all higher than a bandwidth needed by a current service, taking an interface, which supports a network with a lowest rate standard, in the valid network interfaces as the network interface to be switched; or, when bandwidths supported by the valid network interfaces are all higher than a bandwidth needed by a current service and rate standards of networks supported by the valid network interfaces are the same, taking an interface, which supports a highest bandwidth, in the valid network interfaces as the network interface to be switched.