Encoding problems can usually be met in the fields of signal processing, signal transmission, networking and security (key enabling technologies supporting electrical and control engineering applications). With excellent performance, Low-Density Parity-Check Codes is one of the best channel codes. As one of the strongest candidates in the beyond 3th generation communication system, Low-Density Parity-Check Codes is pop currently topic in communication field. In this paper, for the encoding problem of Low-Density Parity-Check Codes, we study the performance and the encoding complexity of the traditional encoding algorithm, the encoding algorithm based on lower triangular parity-check matrix, the encoding algorithm based on approximate lower triangular parity-check matrix, and the encoding algorithm based on the check matrix through greedy algorithm.