A method for service chain policy formulation, wherein the method comprises: receiving, by a policy and charging rules function, PCRF, by using a service capability exposure function, SCEF, a first message sent by an application server, AS, wherein the first message is used to request to formulate a service chain policy for a service flow of a user equipment, UE, and the first message comprises a service chain requirement of the service flow; and formulating, by the PCRF, the service chain policy for the service flow according to the service chain requirement of the service flow that is comprised in the first message, wherein the service chain policy comprises a service chain function provided to the service flow, the method being characterized by, before receiving, by the PCRF by using the SCEF, the first message sent by the AS, the method further comprises: receiving, by the PCRF by using the SCEF, a second message sent by the AS, wherein the second message is used to request to query all service chain functions deployed in the network for the service flow; determining, by the PCRF according to the second message, a first service chain function list, including the service chain functions deployed in the network, that can be provided by the PCRF to the AS; and sending, by the PCRF, a third message to the AS by using the SCEF, wherein the third message comprises the first service chain function list, and the service chain requirement is determined by the AS according to the first service chain function list. receiving, by a policy and charging rules function, PCRF, by using a service capability exposure function, SCEF, a first message sent by an application server, AS, wherein the first message is used to request to formulate a service chain policy for a service flow of a user equipment, UE, and the first message comprises a service chain requirement of the service flow; and formulating, by the PCRF, the service chain policy for the service flow according to the service chain requirement of the service flow that is comprised in the first message, wherein the service chain policy comprises a service chain function provided to the service flow, the method being characterized by, before receiving, by the PCRF by using the SCEF, the first message sent by the AS, the method further comprises: receiving, by the PCRF by using the SCEF, a second message sent by the AS, wherein the second message is used to request to query all service chain functions deployed in the network for the service flow; determining, by the PCRF according to the second message, a first service chain function list, including the service chain functions deployed in the network, that can be provided by the PCRF to the AS; and sending, by the PCRF, a third message to the AS by using the SCEF, wherein the third message comprises the first service chain function list, and the service chain requirement is determined by the AS according to the first service chain function list. receiving, by the PCRF by using the SCEF, a second message sent by the AS, wherein the second message is used to request to query all service chain functions deployed in the network for the service flow; determining, by the PCRF according to the second message, a first service chain function list, including the service chain functions deployed in the network, that can be provided by the PCRF to the AS; and sending, by the PCRF, a third message to the AS by using the SCEF, wherein the third message comprises the first service chain function list, and the service chain requirement is determined by the AS according to the first service chain function list.