The present invention provides an uplink data sending method. The method includes: receiving, by a terminal device, scheduling signaling in at least one downlink time interval in a downlink time interval set, where the scheduling signaling is used to schedule uplink data, and any downlink time interval in the downlink time interval set belongs to a downlink subframe n; determining, by the terminal device, an uplink time interval corresponding to the at least one downlink time interval, where the any downlink time interval in the downlink time interval set is corresponding to the determined uplink time interval, the determined uplink time interval belongs to an uplink subframe n+k, and k is equal to 0, 1, 2, or 3; and sending, by the terminal device, the uplink data in the determined uplink time interval. In the foregoing solution, a latency from receiving scheduling information to sending uplink data can be reduced.