A system information sending method and an apparatus. The method includes receiving, by a base station, at least one first uplink trigger signal in a first time-frequency resource group in a first radio frame, determining, based on a time-frequency resource of the at least one first uplink trigger signal, a time-frequency resource used for sending first system information, where a start location of the time-frequency resource of the first system information in time domain has a first time offset relative to a frame header location of a radio frame in which the first system information is located, and sending the first system information on the time-frequency resource of the first system information.