A resource admission control method provided includes: an NACF receives an authentication request sent by a mobile UE when the mobile UE is moving, and sends a service request to an RACF to trigger the RACF to enforce resource admission control on a transport network. Alternatively, the method includes: a network apparatus in a transport network receives a service access request sent by a mobile UE when the mobile UE is moving, and sends a service request to an RACF to trigger the RACF to enforce resource admission control on the transport network.