A low-density parity-check code scaling method is disclosed. The method includes following steps: obtaining the original low-density parity-check matrix; forming the permutation matrices with the random row shift or the random column shift to the identity matrix; replacing the component codes by the permutation matrices and the all-zero matrix to form the extended low-density parity-check matrix; adjusting the code length and the code rate to form the global coupled low-density parity-check matrix; and outputting the global coupled low-density parity-check code.