Network bandwidth adjustment method and system

The invention provides a network bandwidth adjustment method and a network bandwidth adjustment system. The method comprises the steps of acquiring arrearage data of a user who uses a network from a charging system, wherein the arrearage data comprises an arrearage amount and an arrearage time; judging whether the arrearage of the user is overdue according to the arrearage data; and if yes, adjusting a network bandwidth of the user. According to the network bandwidth adjustment method and system, through acquiring the arrearage data of the group user from the Unicom charging system, the network bandwidth of the group user that has overdue arrearage can be automatically adjusted, so that the condition that the high arrearage generated due to the fact that the group user is not paid for long-term usage of a network service is reduced under the condition that the group user is not disconnected from the network is ensured, and thus the financial loss caused by the high arrearage is avoided, and meanwhile, due to