A data transmission method, comprising: encoding, by a data sending device, information data by using a Raptor-like low-density parity-check, LDPC, code matrix, to obtain a bit sequence, wherein the bit sequence comprises a first bit sequence, and the first bit sequence comprises at least one information bit in the bit sequence; interleaving, by the data sending device, the first bit sequence to obtain a first interleaved bit sequence; and performing, by the data sending device, modulation based on the first interleaved bit sequence to obtain a sending signal, and sending the sending signal; wherein the Raptor-like LDPC code matrix includes a matrix block corresponding to an information bit sequence in a highest bit rate check matrix, a matrix block corresponding to a parity bit sequence in the highest bit rate check matrix, a matrix block extended from the highest bit rate check matrix, a zero matrix, and a matrix whose diagonal is 1 and remaining part is 0; the first bit sequence comprises all information bits in the bit sequence corresponding to the sequence of aligned columns in A and C of the Raptor-like LDPC code matrix and all parity bits in the bit sequence corresponding to the sequence of aligned columns in B and C of the Raptor-like LDPC code matrix whose column weights are greater than 1 and a plurality of parity bits in the bit sequence corresponding to the sequence of aligned columns in O and I of the Raptor-like LDPC code matrix whose column weights are 1, and wherein a number of the plurality of parity bits in the bit sequence corresponding to the sequence of aligned columns in O and I of the Raptor-link LDPC code matrix whose column weights are 1 is selected so that the first bit sequence satisfies the bit rate during initial transmission. encoding, by a data sending device, information data by using a Raptor-like low-density parity-check, LDPC, code matrix, to obtain a bit sequence, wherein the bit sequence comprises a first bit sequence, and the first bit sequence comprises at least one information bit in the bit sequence; interleaving, by the data sending device, the first bit sequence to obtain a first interleaved bit sequence; and performing, by the data sending device, modulation based on the first interleaved bit sequence to obtain a sending signal, and sending the sending signal; wherein the Raptor-like LDPC code matrix includes a matrix block corresponding to an information bit sequence in a highest bit rate check matrix, a matrix block corresponding to a parity bit sequence in the highest bit rate check matrix, a matrix block extended from the highest bit rate check matrix, a zero matrix, and a matrix whose diagonal is 1 and remaining part is 0; the first bit sequence comprises all information bits in the bit sequence corresponding to the sequence of aligned columns in A and C of the Raptor-like LDPC code matrix and all parity bits in the bit sequence corresponding to the sequence of aligned columns in B and C of the Raptor-like LDPC code matrix whose column weights are greater than 1 and a plurality of parity bits in the bit sequence corresponding to the sequence of aligned columns in O and I of the Raptor-like LDPC code matrix whose column weights are 1, and wherein a number of the plurality of parity bits in the bit sequence corresponding to the sequence of aligned columns in O and I of the Raptor-link LDPC code matrix whose column weights are 1 is selected so that the first bit sequence satisfies the bit rate during initial transmission.