A switching method of multiple service flows operation for a WiMAX system, including: - adding a resource combination indication to a handoff request message, a path pre-registration request message and a path registration request message, wherein the resource combination indication is used to indicate whether multiple service flows of a mobile station are bound with each other; - hand-off request processing: determining whether the MS is allowed to hand off to a target network according to the resource combination indication in the hand-off request message and whether the handoff of the multiple service flows is accepted by the target network when the multiple service flows of the MS is handed off from a current serving network to the target network; - path pre-establishment processing: determining whether data paths between the target network and a network where a data management unit is located (anchor ASN) can be pre-established according to the resource combination indication in the path pre-registration request message and the availability of establishing data path pre-registration of the multiple service flows when it is allowed to hand off the multiple service flows of the MS from the current serving network to the target network; and - path establishment processing: determining whether the data paths between the target network and the anchor ASN can be established according to the resource combination indication in the path registration request message and the availability of establishing data path registration of the multiple service flows when it is allowed to hand off the multiple service flows of the MS from the current serving network to the target network and the path pre-registration processing is not performed. - adding a resource combination indication to a handoff request message, a path pre-registration request message and a path registration request message, wherein the resource combination indication is used to indicate whether multiple service flows of a mobile station are bound with each other; - hand-off request processing: determining whether the MS is allowed to hand off to a target network according to the resource combination indication in the hand-off request message and whether the handoff of the multiple service flows is accepted by the target network when the multiple service flows of the MS is handed off from a current serving network to the target network; - path pre-establishment processing: determining whether data paths between the target network and a network where a data management unit is located (anchor ASN) can be pre-established according to the resource combination indication in the path pre-registration request message and the availability of establishing data path pre-registration of the multiple service flows when it is allowed to hand off the multiple service flows of the MS from the current serving network to the target network; and - path establishment processing: determining whether the data paths between the target network and the anchor ASN can be established according to the resource combination indication in the path registration request message and the availability of establishing data path registration of the multiple service flows when it is allowed to hand off the multiple service flows of the MS from the current serving network to the target network and the path pre-registration processing is not performed.