A method for dynamic interface buffer allocation, characterized in that the method comprises: equally dividing a buffer into multiple buffer blocks, each with a size no less than a maximal data-packet size; setting a multi-input multi-output cross matrix between interfaces and the buffer; setting, in advance or while a system is running, a docking relation of an interface requiring buffer access with a buffer block available, and then transferring a data packet received by the interface into the buffer block (101, 501, 503), and connecting, through the cross matrix, an input of the interface to the buffer block; while the system is running, when it is determined that a change in an interface requiring buffer access is required, adjusting, in real time, a docking relation of an interface involved in the change with a buffer block corresponding to the interface involved in the change, when a new interface is to be added, detecting a buffer block available in the system, and connecting, through the cross matrix, an input of the new interface with the detected buffer block available; when an interface is to be withdrawn during the run, disconnecting, from the interface to be withdrawn, a buffer block corresponding to the interface to be withdrawn; when an interface is to be replaced during the run, first disconnecting, from the to-be-replaced interface, a buffer block corresponding to the to-be-replaced interface, and then connecting, through the cross matrix, an input of a replacing interface with the buffer block corresponding to the to-be-replaced interface before the replacement, wherein after an input of an interface requiring buffer access a new interface is connected with a buffer block available, detecting a starting position of a present data packet being input by the interface; after such a position is detected, making the buffer block start receiving the data packet, wherein when the interface requiring buffer access is to be withdrawn, detecting an ending position of a present data packet; after such a position is detected, starting disconnecting, from the interface to be withdrawn, the buffer block corresponding to the interface to be withdrawn, wherein detecting, in real time, connection between a buffer block and an accessing interface, and issuing a warning when it is determined that the buffer block and the accessing interface are not in one-on-one connection. equally dividing a buffer into multiple buffer blocks, each with a size no less than a maximal data-packet size; setting a multi-input multi-output cross matrix between interfaces and the buffer; setting, in advance or while a system is running, a docking relation of an interface requiring buffer access with a buffer block available, and then transferring a data packet received by the interface into the buffer block (101, 501, 503), and connecting, through the cross matrix, an input of the interface to the buffer block; while the system is running, when it is determined that a change in an interface requiring buffer access is required, adjusting, in real time, a docking relation of an interface involved in the change with a buffer block corresponding to the interface involved in the change, when a new interface is to be added, detecting a buffer block available in the system, and connecting, through the cross matrix, an input of the new interface with the detected buffer block available; when an interface is to be withdrawn during the run, disconnecting, from the interface to be withdrawn, a buffer block corresponding to the interface to be withdrawn; when an interface is to be replaced during the run, first disconnecting, from the to-be-replaced interface, a buffer block corresponding to the to-be-replaced interface, and then connecting, through the cross matrix, an input of a replacing interface with the buffer block corresponding to the to-be-replaced interface before the replacement, wherein after an input of an interface requiring buffer access a new interface is connected with a buffer block available, detecting a starting position of a present data packet being input by the interface; after such a position is detected, making the buffer block start receiving the data packet, wherein when the interface requiring buffer access is to be withdrawn, detecting an ending position of a present data packet; after such a position is detected, starting disconnecting, from the interface to be withdrawn, the buffer block corresponding to the interface to be withdrawn, wherein detecting, in real time, connection between a buffer block and an accessing interface, and issuing a warning when it is determined that the buffer block and the accessing interface are not in one-on-one connection.