1. A resource and admission control method comprising: after receiving a resource initialization request for requesting Quality of Service (QoS) resources for services, sent by a service control function (SCF), a policy decision functional entity (PD-FE) of a home operator or retail service provider making an initial policy decision for this request to generate a decision policy; and the PD-FE of the home operator or retail service provider deciding whether the decision policy is required to be installed in a policy enforcement functional entity (PE-FE) of the home operator or retail service provider for the resource initialization request, and sending the resource initialization request to the PE-FE of the home operator or retail service provider to install the decision policy if yes.