A policy management method, wherein the method is applied to a scenario of providing a composite Network Service, NS, across management domains, the composite NS comprises one or more nested NSs, the composite NS and the nested NS forming the composite NS are provided in different management domains; a Network Function Virtualization Orchestrator, NFVO, in a management domain of the composite NS is responsible for Life Cycle Management, LCM, of the composite NS, and an NFVO in a management domain of the nested NS is responsible for life cycle management of the nested NS, wherein the method comprises: sending, by a policy decision entity, a first policy management operation request to the NFVO in the management domain of the composite NS, wherein the first policy management operation request comprises an identifier of a policy group; and receiving, by the NFVO in the management domain of the composite NS, the first policy management operation request, determining, based on the identifier of the policy group, an identifier of an LCM policy that is of the nested NS and that is comprised in the policy group, and sending a second policy management operation request to the NFVO in the management domain of the nested NS, wherein the second policy management operation request comprises the identifier of the LCM policy of the nested NS, wherein before the sending, by a policy decision entity, a first policy management operation request to the NFVO in the management domain of the composite NS, the method further comprises: requesting, by the policy decision entity, the NFVO in the management domain of the composite NS to create a policy group, wherein the policy group creation requesting comprises an identifier of a member policy of the policy group, and the member policy comprises an LCM policy of one composite NS and LCM policies of one or more nested NSs forming the composite NS; creating, by the NFVO in the management domain of the composite NS, the policy group based on the policy group creation requesting, allocating an identifier to the policy group, and sending a response message to the policy decision entity, wherein the response message comprises the identifier of the policy group; and obtaining and recording, by the policy decision entity in the received response message that is for the policy group creation request and that is sent by the NFVO in the management domain of the composite NS, the identifier allocated to the policy group by the NFVO in the management domain of the composite NS. sending, by a policy decision entity, a first policy management operation request to the NFVO in the management domain of the composite NS, wherein the first policy management operation request comprises an identifier of a policy group; and receiving, by the NFVO in the management domain of the composite NS, the first policy management operation request, determining, based on the identifier of the policy group, an identifier of an LCM policy that is of the nested NS and that is comprised in the policy group, and sending a second policy management operation request to the NFVO in the management domain of the nested NS, wherein the second policy management operation request comprises the identifier of the LCM policy of the nested NS, wherein before the sending, by a policy decision entity, a first policy management operation request to the NFVO in the management domain of the composite NS, the method further comprises: requesting, by the policy decision entity, the NFVO in the management domain of the composite NS to create a policy group, wherein the policy group creation requesting comprises an identifier of a member policy of the policy group, and the member policy comprises an LCM policy of one composite NS and LCM policies of one or more nested NSs forming the composite NS; creating, by the NFVO in the management domain of the composite NS, the policy group based on the policy group creation requesting, allocating an identifier to the policy group, and sending a response message to the policy decision entity, wherein the response message comprises the identifier of the policy group; and obtaining and recording, by the policy decision entity in the received response message that is for the policy group creation request and that is sent by the NFVO in the management domain of the composite NS, the identifier allocated to the policy group by the NFVO in the management domain of the composite NS. requesting, by the policy decision entity, the NFVO in the management domain of the composite NS to create a policy group, wherein the policy group creation requesting comprises an identifier of a member policy of the policy group, and the member policy comprises an LCM policy of one composite NS and LCM policies of one or more nested NSs forming the composite NS; creating, by the NFVO in the management domain of the composite NS, the policy group based on the policy group creation requesting, allocating an identifier to the policy group, and sending a response message to the policy decision entity, wherein the response message comprises the identifier of the policy group; and obtaining and recording, by the policy decision entity in the received response message that is for the policy group creation request and that is sent by the NFVO in the management domain of the composite NS, the identifier allocated to the policy group by the NFVO in the management domain of the composite NS.