Embodiments of the present invention relate to the field of communications technologies, and provide an information transmission method and apparatus, to flexibly set a quantity of subframes in subframe aggregation and a redundancy version based on a channel condition. The method includes: sending, by a first device, downlink control information to a second device, where the downlink control information includes subframe aggregation information, and the subframe aggregation information is used by the first device to indicate, to the second device, a quantity of subframes used in subframe aggregation and/or a redundancy version corresponding to at least one of subframes used in subframe aggregation; and receiving, by the first device, uplink information sent by the second device according to the downlink control information. The embodiments of the present invention are used for subframe aggregation.