A congestion control implementation method executed by a mobility management entity MME, and comprises: determining one or more user equipments for which single radio voice call continuity SRVCC offloading needs to be performed; and sending an SRVCC offload message to an E-UTRAN NodeB eNodeB serving the one or more user equipments, so that when triggering an SRVCC handover procedure, the E-UTRAN NodeB switches the one or more user equipments from a Long Term Evolution LTE domain to a circuit switched CS domain; wherein before the determining one or more user equipments, the method further comprises: determining that the MME is in congestion state; wherein the determining that the MME is in congestion state comprises: determining that the MME is in congestion state according to cell congestion information sent by a network side device, wherein the cell congestion information comprises a cell congestion level and cell information; or collecting statistics about a quality-of-service class identifier QCI bearer setup success rate, and when the QCI bearer setup success rate is less than a preset threshold, determining that the MME is in congestion state. determining one or more user equipments for which single radio voice call continuity SRVCC offloading needs to be performed; and sending an SRVCC offload message to an E-UTRAN NodeB eNodeB serving the one or more user equipments, so that when triggering an SRVCC handover procedure, the E-UTRAN NodeB switches the one or more user equipments from a Long Term Evolution LTE domain to a circuit switched CS domain; wherein before the determining one or more user equipments, the method further comprises: determining that the MME is in congestion state; wherein the determining that the MME is in congestion state comprises: determining that the MME is in congestion state according to cell congestion information sent by a network side device, wherein the cell congestion information comprises a cell congestion level and cell information; or collecting statistics about a quality-of-service class identifier QCI bearer setup success rate, and when the QCI bearer setup success rate is less than a preset threshold, determining that the MME is in congestion state. determining that the MME is in congestion state; wherein the determining that the MME is in congestion state comprises: determining that the MME is in congestion state according to cell congestion information sent by a network side device, wherein the cell congestion information comprises a cell congestion level and cell information; or collecting statistics about a quality-of-service class identifier QCI bearer setup success rate, and when the QCI bearer setup success rate is less than a preset threshold, determining that the MME is in congestion state. determining that the MME is in congestion state according to cell congestion information sent by a network side device, wherein the cell congestion information comprises a cell congestion level and cell information; or collecting statistics about a quality-of-service class identifier QCI bearer setup success rate, and when the QCI bearer setup success rate is less than a preset threshold, determining that the MME is in congestion state.