A method for updating a User Equipment, UE, policy to a first UE policy, the method being implemented by a UE, the method comprising: receiving, by the UE, the first UE policy and first indication information from a network device; wherein the method further comprises: performing updating of an existing association between an application data stream and a Protocol Data Unit, PDU, session based on the first UE policy, wherein the first indication information comprises a first indication parameter, and the first indication parameter is configured to instruct the UE to determine a state of a first application data stream in a UE Route Selection Policy, URSP, rule based on the first UE policy and execute an operation of updating an association between the first application data stream and a PDU session based on the state of the first application data stream; wherein executing the operation of updating the association between the first application data stream and the PDU session based on the state of the first application data stream is in response to that the state of the first application data stream is an inactive state, wherein the state of the first application data stream being the inactive state refers to that the first application data stream comprises no data packet or only comprises a heartbeat packet at present or in a period of time, or in response to that the state of the first application data stream indicates that a rate of the first application data stream is lower than a certain threshold. receiving, by the UE, the first UE policy and first indication information from a network device; wherein the method further comprises: performing updating of an existing association between an application data stream and a Protocol Data Unit, PDU, session based on the first UE policy, wherein the first indication information comprises a first indication parameter, and the first indication parameter is configured to instruct the UE to determine a state of a first application data stream in a UE Route Selection Policy, URSP, rule based on the first UE policy and execute an operation of updating an association between the first application data stream and a PDU session based on the state of the first application data stream; wherein executing the operation of updating the association between the first application data stream and the PDU session based on the state of the first application data stream is in response to that the state of the first application data stream is an inactive state, wherein the state of the first application data stream being the inactive state refers to that the first application data stream comprises no data packet or only comprises a heartbeat packet at present or in a period of time, or in response to that the state of the first application data stream indicates that a rate of the first application data stream is lower than a certain threshold. performing updating of an existing association between an application data stream and a Protocol Data Unit, PDU, session based on the first UE policy, wherein the first indication information comprises a first indication parameter, and the first indication parameter is configured to instruct the UE to determine a state of a first application data stream in a UE Route Selection Policy, URSP, rule based on the first UE policy and execute an operation of updating an association between the first application data stream and a PDU session based on the state of the first application data stream; wherein executing the operation of updating the association between the first application data stream and the PDU session based on the state of the first application data stream is in response to that the state of the first application data stream is an inactive state, wherein the state of the first application data stream being the inactive state refers to that the first application data stream comprises no data packet or only comprises a heartbeat packet at present or in a period of time, or in response to that the state of the first application data stream indicates that a rate of the first application data stream is lower than a certain threshold.