The present disclosure relates to low-density parity-check (LDPC) encoding methods and apparatus. One example method includes obtaining k information bits to be sent to a receive end, performing LDPC encoding on the k information bits by using a submatrix of ((n−k)/Z+j) rows and (n/Z+j) columns at an upper left corner of a check matrix H based on a first transmission code rate R satisfying R=k/(n+j×Z), obtaining a first codeword including the k information bits and (n−k+j×Z) redundant bits, and sending the first codeword to the receive end.