A channel estimation information transmission method, comprising: determining, by an apparatus, a high efficiency long training field, HE-LTF, sequence in frequency domain according to a transmission bandwidth and a mode of a HE-LTF field, for a high efficiency, HE, physical protocol data unit, PPDU; sending, by the apparatus, a time-domain signal of the HE PPDU, according to a number of orthogonal frequency division multiplexing, OFDM, symbols of the HE-LTF field, N HELTF, and the determined HE-LTF sequence in the frequency domain; characterized in that the HE-LTF sequence in the frequency domain in a 1x HE-LTF mode over a 160 MHz bandwidth corresponds to: HE-LTF = [P1×LTF 80MHz_Primary, BI, P2×LTF 80MHz_Secondary], wherein P1 is +1, P2 is +1 or -1, LTF 80MHz_Primary = {L-LTF 80MHz_A, 0, R-LTF 80MHz_A}, the LTF 80MHz_Primary is a long training sequence of a primary 80 MHz channel, LTF 80MHz_Secondary = {L-LTF 80MHz_A, 0, -1×R-LTF 80MHz_A}, the LTF 80MHz_Secondary is a long training sequence of a secondary 80 MHz channel, and wherein the BI is a sequence carried on subcarriers between subcarriers on edges of two 80 MHz channels; wherein {L-LTF 80MHz_A, 0, R-LTF 80MHz_A} = HE-LTF 250 (-500:4:500), and HE-LTF 250 (-500:4:500) = {-1, -1, +1, +1, +1, +1, +1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, -1, -1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, -1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, - 1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, -1, +1, -1, -1, -1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1,-1, -1, +1, -1, +1, -1, -1, 0, -1, +1, +1, -1, -1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1,-1, -1, +1, +1, -1, -1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, +1,-1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, -1, +1, -1, +1, -1, -1, -1, +1, +1}, wherein -500:4:500 indicates that values on subcarriers with indexes -500, -496,..., -8, -4, 0, 4, 8,..., 496, and 500 are successively the foregoing values, and values on remaining subcarriers are 0. determining, by an apparatus, a high efficiency long training field, HE-LTF, sequence in frequency domain according to a transmission bandwidth and a mode of a HE-LTF field, for a high efficiency, HE, physical protocol data unit, PPDU; sending, by the apparatus, a time-domain signal of the HE PPDU, according to a number of orthogonal frequency division multiplexing, OFDM, symbols of the HE-LTF field, N HELTF, and the determined HE-LTF sequence in the frequency domain; characterized in that the HE-LTF sequence in the frequency domain in a 1x HE-LTF mode over a 160 MHz bandwidth corresponds to: HE-LTF = [P1×LTF 80MHz_Primary, BI, P2×LTF 80MHz_Secondary], wherein P1 is +1, P2 is +1 or -1, LTF 80MHz_Primary = {L-LTF 80MHz_A, 0, R-LTF 80MHz_A}, the LTF 80MHz_Primary is a long training sequence of a primary 80 MHz channel, LTF 80MHz_Secondary = {L-LTF 80MHz_A, 0, -1×R-LTF 80MHz_A}, the LTF 80MHz_Secondary is a long training sequence of a secondary 80 MHz channel, and wherein the BI is a sequence carried on subcarriers between subcarriers on edges of two 80 MHz channels; HE-LTF = [P1×LTF 80MHz_Primary, BI, P2×LTF 80MHz_Secondary], wherein P1 is +1, P2 is +1 or -1, LTF 80MHz_Primary = {L-LTF 80MHz_A, 0, R-LTF 80MHz_A}, the LTF 80MHz_Primary is a long training sequence of a primary 80 MHz channel, LTF 80MHz_Secondary = {L-LTF 80MHz_A, 0, -1×R-LTF 80MHz_A}, the LTF 80MHz_Secondary is a long training sequence of a secondary 80 MHz channel, wherein {L-LTF 80MHz_A, 0, R-LTF 80MHz_A} = HE-LTF 250 (-500:4:500), and HE-LTF 250 (-500:4:500) = {-1, -1, +1, +1, +1, +1, +1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, -1, -1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, -1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1, +1, - 1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, -1, +1, -1, -1, -1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1,-1, -1, +1, -1, +1, -1, -1, 0, -1, +1, +1, -1, -1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1,-1, -1, +1, +1, -1, -1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, -1, +1, +1,-1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, -1, +1, -1, +1, -1, -1, -1, +1, +1}, wherein -500:4:500 indicates that values on subcarriers with indexes -500, -496,..., -8, -4, 0, 4, 8,..., 496, and 500 are successively the foregoing values, and values on remaining subcarriers are 0.