An information sending method, applied to a wireless communication system, wherein the wireless communication system comprises a first terminal and a second terminal, there is one or more second terminals, and the method comprises: sending, by the first terminal, a first indication message to the second terminal, wherein the first indication message indicates the second terminal to report first information; reporting, by the second terminal, the first information to the first terminal according to the first indication message, wherein the first information indicates channel state information of a channel resource; and sending, by the first terminal, a second indication message to the second terminal, wherein the second indication message indicates information about a first resource set, the first resource set is determined by the first terminal based on the first information, and a resource in the first resource set is a resource for sidelink communication, wherein the channel state information of a channel resource is first-type state information, and the first-type state information indicates whether channel quality of the channel resource reaches a first threshold; or the channel state information of a channel resource is second-type state information, and the second-type state information is channel quality of the channel resource; or the channel state information of a channel resource is third-type state information, and the third-type state information indicates whether a bit error rate of the channel resource reaches a second threshold; and the channel quality comprises reference signal received power RSRP, a signal to interference plus noise ratio SINR, or reference signal received quality RSRQ, wherein the channel state information of the channel resource is switched from the first-type state information to the third-type state information after data transmission is performed for a period of time, and the channel state information of the channel resource is switched from the third-type state information to the second-type state information based on the bit error rate of the channel resource. sending, by the first terminal, a first indication message to the second terminal, wherein the first indication message indicates the second terminal to report first information; reporting, by the second terminal, the first information to the first terminal according to the first indication message, wherein the first information indicates channel state information of a channel resource; and sending, by the first terminal, a second indication message to the second terminal, wherein the second indication message indicates information about a first resource set, the first resource set is determined by the first terminal based on the first information, and a resource in the first resource set is a resource for sidelink communication, wherein the channel state information of a channel resource is first-type state information, and the first-type state information indicates whether channel quality of the channel resource reaches a first threshold; or the channel state information of a channel resource is second-type state information, and the second-type state information is channel quality of the channel resource; or the channel state information of a channel resource is third-type state information, and the third-type state information indicates whether a bit error rate of the channel resource reaches a second threshold; and the channel quality comprises reference signal received power RSRP, a signal to interference plus noise ratio SINR, or reference signal received quality RSRQ, wherein the channel state information of the channel resource is switched from the first-type state information to the third-type state information after data transmission is performed for a period of time, and the channel state information of the channel resource is switched from the third-type state information to the second-type state information based on the bit error rate of the channel resource.