A method and apparatus for bandwidth adjustment in a network virtualization system is described herein. The network virtualization system includes a central module and m remote modules, where the m remote modules are connected to a physical interface of the central module by n PWs. The method includes: acquiring, from the m remote modules, a real-time bandwidth of each PW of the n PWs; when a sum of the acquired real-time bandwidths of the n PWs is greater than a bandwidth of the physical interface, adjusting configured bandwidths of P PWs; and separately sending values of adjusted configured bandwidths of the P PWs to the remote modules separately connected to the P PWs.