An information processing method in a communications system, comprising: obtaining, by a communication device, an input sequence of length B; determining, by the communication device, that the input sequence is to be segmented into C code blocks based on the length B of the input sequence and a maximum code block length Z, where B > Z; performing, by the communication device, segmentation on the input sequence to obtain the C code blocks; wherein each of the C code blocks comprises a bit segment, a cyclic redundancy check, CRC, bit segment, and a filler bit segment, wherein each bit segment comprises one or more bits from the input sequence, each CRC bit segment comprises L CRC bits for a corresponding bit segment, and B, Z, C, and L are integers greater than 0, wherein B, Z, C, and L meet C = ┌ B /( Z-L) ┐, where [·] represents rounding to an upper integer, and at least one of the C code blocks comprises a segment of length K 3, wherein the segment of length K 3 comprises a bit segment and a CRC bit segment, and K 3 meets K 3 = ┌ ( B + C·L)/ C ┐, wherein, in the code block comprising the segment of length K 5, the filler bit segment comprises F 3 filler bits, where F 3 = I 3 - K 3, wherein I 3 is a product of a lifting factor z and a value X, wherein the value X is a quantity of columns corresponding to information bits in a low-density parity-check, LDPC, base matrix for encoding each of the C code blocks, and wherein the lifting factor z is a minimum value in lifting factors greater than or equal to ┌ K 3 /X ┐, where F 3 is an integer greater than 0, or the lifting factor z is a minimum value in lifting factors that makes I 3 meet I 3 ≥ K 3, where I 3 is greater than or equal to K 3, and F 3 is an integer greater than 0; and encoding, by the communication device each of the C code blocks with said LDPC base matrix. obtaining, by a communication device, an input sequence of length B; determining, by the communication device, that the input sequence is to be segmented into C code blocks based on the length B of the input sequence and a maximum code block length Z, where B > Z; performing, by the communication device, segmentation on the input sequence to obtain the C code blocks; wherein each of the C code blocks comprises a bit segment, a cyclic redundancy check, CRC, bit segment, and a filler bit segment, wherein each bit segment comprises one or more bits from the input sequence, each CRC bit segment comprises L CRC bits for a corresponding bit segment, and B, Z, C, and L are integers greater than 0, wherein B, Z, C, and L meet C = ┌ B /( Z-L) ┐, where [·] represents rounding to an upper integer, and at least one of the C code blocks comprises a segment of length K 3, wherein the segment of length K 3 comprises a bit segment and a CRC bit segment, and K 3 meets K 3 = ┌ ( B + C·L)/ C ┐, wherein, in the code block comprising the segment of length K 5, the filler bit segment comprises F 3 filler bits, where F 3 = I 3 - K 3, wherein I 3 is a product of a lifting factor z and a value X, wherein the value X is a quantity of columns corresponding to information bits in a low-density parity-check, LDPC, base matrix for encoding each of the C code blocks, and wherein the lifting factor z is a minimum value in lifting factors greater than or equal to ┌ K 3 /X ┐, where F 3 is an integer greater than 0, or the lifting factor z is a minimum value in lifting factors that makes I 3 meet I 3 ≥ K 3, where I 3 is greater than or equal to K 3, and F 3 is an integer greater than 0; and encoding, by the communication device each of the C code blocks with said LDPC base matrix.