A service setting method performed by a system comprising a call session control function, CSCF, and a service setting saving entity, the method comprising: • receiving (201, 204, 208, 211, 301, 304, 310, 313), by the CSCF, service registration requests of user equipments, UEs, and sending answer messages of successful registration to the UEs; • after the sending answer messages of the successful registration to the UEs, receiving (101, 103, 205, 212, 307, 316), by the service setting saving entity, user setting information, a user identifier, user equipment, UE, setting information, and UE identifiers uploaded by the UEs of the same user; wherein the service is a Push to Talk over cellular, PoC service and • bindingly saving (102, 105, 206, 213, 308, 317), by the service setting saving entity, the user setting information and the user identifier, and bindingly saving the UE identifier and the UE setting information of the same user, • wherein between the receiving, by the CSCF, the service registration requests of the UEs and sending the answer messages of successful registration to the UEs and the receiving, by the service setting saving entity, the user setting information, the user identifier, the UE setting information, and the UE identifiers uploaded by the UEs of the same user, the method further comprises: ∘ receiving (305, 314), by the service setting saving entity,, a user identifier and UE identifiers sent by the CSCF; and • after the receiving, by the service setting saving entity, the user setting information, the user identifier, the UE setting information, and the UE identifiers uploaded by the UEs, the method further comprises: ∘ verifying (306, 315), by the service setting saving entity, the user identifier and the UE identifiers uploaded by the UEs according to the user identifier and the UE identifiers obtained from the CSCF. • receiving (201, 204, 208, 211, 301, 304, 310, 313), by the CSCF, service registration requests of user equipments, UEs, and sending answer messages of successful registration to the UEs; • after the sending answer messages of the successful registration to the UEs, receiving (101, 103, 205, 212, 307, 316), by the service setting saving entity, user setting information, a user identifier, user equipment, UE, setting information, and UE identifiers uploaded by the UEs of the same user; wherein the service is a Push to Talk over cellular, PoC service and • bindingly saving (102, 105, 206, 213, 308, 317), by the service setting saving entity, the user setting information and the user identifier, and bindingly saving the UE identifier and the UE setting information of the same user, • wherein between the receiving, by the CSCF, the service registration requests of the UEs and sending the answer messages of successful registration to the UEs and the receiving, by the service setting saving entity, the user setting information, the user identifier, the UE setting information, and the UE identifiers uploaded by the UEs of the same user, the method further comprises: ∘ receiving (305, 314), by the service setting saving entity,, a user identifier and UE identifiers sent by the CSCF; and ∘ receiving (305, 314), by the service setting saving entity,, a user identifier and UE identifiers sent by the CSCF; and • after the receiving, by the service setting saving entity, the user setting information, the user identifier, the UE setting information, and the UE identifiers uploaded by the UEs, the method further comprises: ∘ verifying (306, 315), by the service setting saving entity, the user identifier and the UE identifiers uploaded by the UEs according to the user identifier and the UE identifiers obtained from the CSCF. ∘ verifying (306, 315), by the service setting saving entity, the user identifier and the UE identifiers uploaded by the UEs according to the user identifier and the UE identifiers obtained from the CSCF.