Ahigh-speed data transmission degradation method performed by a network-side device, comprising: receiving (S402), by the network-side device, a degradation request sent by a terminal that is in a high-speed data transmission mode, wherein the degradation request comprises a carrier aggregation, CA degradation parameter and/or a multiple-input multiple-output, MIMO degradation parameter, the CA degradation parameter is used to instruct the network-side device to perform CA degradation on the terminal, and the MIMO degradation parameter is used to instruct the network-side device to perform MIMO degradation on the terminal; obtaining (S403), by the network-side device, a target to-be-degraded resource of the terminal based on the degradation request, wherein the target to-be-degraded resource comprises at least one CA component carrier that is to be deactivated when the network-side device performs CA component carrier degradation on the terminal, and/or a quantity of MIMO service flows that is to be deducted when the network-side device performs MIMO degradation on the terminal; and degrading (S404), by the network-side device, the target to-be-degraded resource, characterized in that after the receiving, by the network-side device, the degradation request sent by a terminal that is in a high-speed data transmission mode, the method further comprises: determining (S407) whether the terminal is capable of proactively initiating degradation from a capability indication message sent by the terminal before the degradation request; and the obtaining, by the network-side device, a target to-be-degraded resource of the terminal comprises: obtaining, by the network-side device, the target to-be-degraded resource of the terminal if the terminal is capable of proactively initiating degradation. receiving (S402), by the network-side device, a degradation request sent by a terminal that is in a high-speed data transmission mode, wherein the degradation request comprises a carrier aggregation, CA degradation parameter and/or a multiple-input multiple-output, MIMO degradation parameter, the CA degradation parameter is used to instruct the network-side device to perform CA degradation on the terminal, and the MIMO degradation parameter is used to instruct the network-side device to perform MIMO degradation on the terminal; obtaining (S403), by the network-side device, a target to-be-degraded resource of the terminal based on the degradation request, wherein the target to-be-degraded resource comprises at least one CA component carrier that is to be deactivated when the network-side device performs CA component carrier degradation on the terminal, and/or a quantity of MIMO service flows that is to be deducted when the network-side device performs MIMO degradation on the terminal; and degrading (S404), by the network-side device, the target to-be-degraded resource, characterized in that after the receiving, by the network-side device, the degradation request sent by a terminal that is in a high-speed data transmission mode, the method further comprises: determining (S407) whether the terminal is capable of proactively initiating degradation from a capability indication message sent by the terminal before the degradation request; and the obtaining, by the network-side device, a target to-be-degraded resource of the terminal comprises: obtaining, by the network-side device, the target to-be-degraded resource of the terminal if the terminal is capable of proactively initiating degradation. determining (S407) whether the terminal is capable of proactively initiating degradation from a capability indication message sent by the terminal before the degradation request; and the obtaining, by the network-side device, a target to-be-degraded resource of the terminal comprises: obtaining, by the network-side device, the target to-be-degraded resource of the terminal if the terminal is capable of proactively initiating degradation. <EOS>