N time-frequency resources are determined by a first communications device. Any two of the N time-frequency resources are nonconsecutive in at least one of a time domain and a frequency domain; each of the N time-frequency resources is smaller than a time-frequency resource required for transmitting to-be-transmitted data, a sum of the N time-frequency resources is greater than or equal to the time-frequency resource required for transmitting the to-be-transmitted data and N is a positive integer greater than or equal to 2. First indication information is sent on M of the N time-frequency resources. The first indication information is used to indicate that the N time-frequency resources are used to send the to-be-transmitted data, M is a positive integer less than or equal to N. The to-be-transmitted data are sent on the N time-frequency resources so that time-frequency resource utilization is improved.