A sounding reference signal sending method, a sounding reference signal receiving method, an apparatus, and a system relating to the field of communications technologies to improve SRS resource utilization and reduce resource waste are disclosed. The method includes: receiving, by a terminal device, SRS configuration information sent by a network side device, where the SRS configuration information includes first-type indication information used to instruct the terminal device to trigger, based on uplink data, sending of an SRS; and once there is the uplink data needing to be transmitted, sending the SRS on an SRS resource.