A control information processing method, comprising: receiving, by a first device (600, 700), first control information sent by a network device; determining, by the first device (600, 700) based on first information, that the first control information is used to schedule a target device, wherein the target device is one of the following devices: the first device (600, 700) and at least one second device (800, 900), the at least one second device (800, 900) communicates with the network device by using the first device (600, 700), and the first information comprises a payload size of the first control information, wherein mapping relationships between different payload sizes and different device identities are set, and the first information further comprises at least one of the following: the first control information, a radio network temporary identifier for scrambling the first control information, a Physical Downlink Control Channel, PDCCH, that carries the first control information, and a subframe in which the first control information is located; and when the target device is the at least one second device (800, 900), determining, by the first device (600, 700), second control information based on resource information that is used for data transmission and that is comprised in the first control information, and sending the second control information to the target device, so that the target device transmits data based on the second control information; or when the target device is the first device (600, 700), transmitting, by the first device (600, 700), data based on the first control information. receiving, by a first device (600, 700), first control information sent by a network device; determining, by the first device (600, 700) based on first information, that the first control information is used to schedule a target device, wherein the target device is one of the following devices: the first device (600, 700) and at least one second device (800, 900), the at least one second device (800, 900) communicates with the network device by using the first device (600, 700), and the first information comprises a payload size of the first control information, wherein mapping relationships between different payload sizes and different device identities are set, and the first information further comprises at least one of the following: the first control information, a radio network temporary identifier for scrambling the first control information, a Physical Downlink Control Channel, PDCCH, that carries the first control information, and a subframe in which the first control information is located; and when the target device is the at least one second device (800, 900), determining, by the first device (600, 700), second control information based on resource information that is used for data transmission and that is comprised in the first control information, and sending the second control information to the target device, so that the target device transmits data based on the second control information; or when the target device is the first device (600, 700), transmitting, by the first device (600, 700), data based on the first control information.