A data sending method, comprising: receiving a threshold; if a data volume of a packet to be sent is less than the threshold, sending the packet in a first data transmission manner; and if a data volume of the packet is greater than or equal to the threshold, sending the packet in a second data transmission manner wherein a multiplexing manner for a transmission resource used in the first data transmission manner and a transmission resource used in the second data transmission manner is frequency division multiplexing, and a data format used in the first data transmission manner sequentially comprises an information code word field, a plurality of OFDM symbols formed by the packet, and a guard time GT, wherein the information code word field is used to indicate a start position of the OFDM symbols, and the information code word field comprises a cyclic prefix CP, the CP is greater than or equal to a sum of the double of a propagation delay and a maximum multipath delay spread in a current transmission environment, wherein: the GT in the data format used in the first data transmission manner is greater than the double of the propagation delay in the current transmission environment, and wherein a data format used in the second data transmission manner is: cyclic prefix, CP, plus one OFDM symbol plus guard time, GT, in the stated sequence, the CP in the data format used in the first data transmission manner is greater than the duration of the CP in the data format used in the second data transmission manner, and a duration of the plurality of OFDM symbols in the data format used in the first data transmission manner is an integer multiple of a duration of the one OFDM symbol in the data format used in the second data transmission manner. receiving a threshold; if a data volume of a packet to be sent is less than the threshold, sending the packet in a first data transmission manner; and if a data volume of the packet is greater than or equal to the threshold, sending the packet in a second data transmission manner wherein a multiplexing manner for a transmission resource used in the first data transmission manner and a transmission resource used in the second data transmission manner is frequency division multiplexing, and a data format used in the first data transmission manner sequentially comprises an information code word field, a plurality of OFDM symbols formed by the packet, and a guard time GT, wherein the information code word field is used to indicate a start position of the OFDM symbols, and the information code word field comprises a cyclic prefix CP, the CP is greater than or equal to a sum of the double of a propagation delay and a maximum multipath delay spread in a current transmission environment, wherein: the GT in the data format used in the first data transmission manner is greater than the double of the propagation delay in the current transmission environment, and wherein a data format used in the second data transmission manner is: cyclic prefix, CP, plus one OFDM symbol plus guard time, GT, in the stated sequence, the CP in the data format used in the first data transmission manner is greater than the duration of the CP in the data format used in the second data transmission manner, and a duration of the plurality of OFDM symbols in the data format used in the first data transmission manner is an integer multiple of a duration of the one OFDM symbol in the data format used in the second data transmission manner. the GT in the data format used in the first data transmission manner is greater than the double of the propagation delay in the current transmission environment, and wherein a data format used in the second data transmission manner is: cyclic prefix, CP, plus one OFDM symbol plus guard time, GT, in the stated sequence, the CP in the data format used in the first data transmission manner is greater than the duration of the CP in the data format used in the second data transmission manner, and a duration of the plurality of OFDM symbols in the data format used in the first data transmission manner is an integer multiple of a duration of the one OFDM symbol in the data format used in the second data transmission manner.