With reference to any one of the first possible implementation manner to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, after the sending, by the first network device, at least one physical downlink control channel of the physical downlink control channel in the at least one subset to the user equipment, the method further includes: if the second network device receives negative acknowledgement information sent by the user equipment, sending, by the second network device to the user equipment, at least one of the physical downlink control channel that is for retransmission and in the second resource set group, where the at least one of the physical downlink control channel for retransmission carries second control information, and the second control information includes scheduling information of downlink data corresponding to the at least one of the physical downlink control channel for retransmission; or