An uplink control information, UCI sending method, comprising: receiving, by a terminal device, channel indication information from an access network device on a physical control channel; determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set, wherein N is a positive integer greater than or equal to 2, the N channel resource sets are preconfigured by the access network device for the terminal device, and each of the N channel resource sets comprises at least two channel resources, wherein before the determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set, the method further comprises: determining, by the terminal device, a size of the UCI, wherein the UCI includes channel state information, CSI; and the determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set comprises: determining, by the terminal device, the channel resource set that is of the N channel resource sets and that matches the size of the UCI as the first channel resource set; determining, by the terminal device, a channel resource that is in the first channel resource set and that is indicated by the channel indication information; and sending, by the terminal device, the UCI, to the access network device on the channel resource. receiving, by a terminal device, channel indication information from an access network device on a physical control channel; determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set, wherein N is a positive integer greater than or equal to 2, the N channel resource sets are preconfigured by the access network device for the terminal device, and each of the N channel resource sets comprises at least two channel resources, wherein before the determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set, the method further comprises: determining, by the terminal device, a size of the UCI, wherein the UCI includes channel state information, CSI; and the determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set comprises: determining, by the terminal device, the channel resource set that is of the N channel resource sets and that matches the size of the UCI as the first channel resource set; determining, by the terminal device, a channel resource that is in the first channel resource set and that is indicated by the channel indication information; and sending, by the terminal device, the UCI, to the access network device on the channel resource. determining, by the terminal device, a size of the UCI, wherein the UCI includes channel state information, CSI; and the determining, by the terminal device, a channel resource set of N channel resource sets as a first channel resource set comprises: determining, by the terminal device, the channel resource set that is of the N channel resource sets and that matches the size of the UCI as the first channel resource set; determining, by the terminal device, a channel resource that is in the first channel resource set and that is indicated by the channel indication information; and sending, by the terminal device, the UCI, to the access network device on the channel resource. determining, by the terminal device, the channel resource set that is of the N channel resource sets and that matches the size of the UCI as the first channel resource set; determining, by the terminal device, a channel resource that is in the first channel resource set and that is indicated by the channel indication information; and sending, by the terminal device, the UCI, to the access network device on the channel resource.