A method for controlling services, comprising: obtaining, by a policy control and charging rules function entity PCRF, congestion state information on a cell, resource-related information on the cell, and subscriber-related information on a user equipment UE in an activated state in the cell that are sent by an access network device; generating, by the PCRF, a quality of service QoS policy and/or a charging policy for the UE in the activated state in the cell according to the congestion state information on the cell, the resource-related information on the cell, and the subscriber-related information on the UE in the activated state in the cell; and sending, by the PCRF, the QoS policy and/or the charging policy to a policy and charging enforcement function entity PCEF, so as to enable the PCEF to execute the QoS policy and/or the charging policy; wherein the subscriber-related information on the UE in the activated state in the cell comprises subscriber list information on the UE in the activated state in the cell and change information on the UE in the activated state in the cell, wherein the subscriber list information includes one or more pieces of UE identification information; whereby the method further comprises: sending, by the PCRF, signaling for detecting a change of the UE in the activated state in the cell, through the PCEF or an operation and maintenance OM system or directly to the access network device, to instruct the access network device to send the information on the UE in the activated state that changes when the access network device detects that the UE in the activated state in the cell changes; and receiving, by the PCRF, at least one type of the following information sent through the PCEF or the OM system or directly by the access network device: identification information on a UE in the activated state that changes from a deactivated state to an activated state, identification information on a UE in the deactivated state that changes from the activated state to the deactivated state, identification information on a UE in the activated state that leaves the cell, and identification information on a UE in the activated state that enters the cell. obtaining, by a policy control and charging rules function entity PCRF, congestion state information on a cell, resource-related information on the cell, and subscriber-related information on a user equipment UE in an activated state in the cell that are sent by an access network device; generating, by the PCRF, a quality of service QoS policy and/or a charging policy for the UE in the activated state in the cell according to the congestion state information on the cell, the resource-related information on the cell, and the subscriber-related information on the UE in the activated state in the cell; and sending, by the PCRF, the QoS policy and/or the charging policy to a policy and charging enforcement function entity PCEF, so as to enable the PCEF to execute the QoS policy and/or the charging policy; sending, by the PCRF, signaling for detecting a change of the UE in the activated state in the cell, through the PCEF or an operation and maintenance OM system or directly to the access network device, to instruct the access network device to send the information on the UE in the activated state that changes when the access network device detects that the UE in the activated state in the cell changes; and receiving, by the PCRF, at least one type of the following information sent through the PCEF or the OM system or directly by the access network device: identification information on a UE in the activated state that changes from a deactivated state to an activated state, identification information on a UE in the deactivated state that changes from the activated state to the deactivated state, identification information on a UE in the activated state that leaves the cell, and identification information on a UE in the activated state that enters the cell.