The present invention discloses an information transmission method, a device, and a system, relates to the communications field, and can resolve a problem of inappropriate time-frequency resource allocation in a device-to-device technology. A specific solution is as follows: user equipment obtains discovery information, generates request information according to the discovery information, sends the request information to a base station, receives resource information sent by the base station, and sends the discovery information to other user equipment according to an effective time-frequency resource included in the resource information. The present invention is used for information transmission.