The invention discloses an encoder of an LDPC code with a layered quasi-cyclic extension structure, comprising: an input buffer, a first processing-buffering pipeline stage, a second processing pipeline stage, a third buffering pipeline stage, and a fourth processing-buffering pipeline stage and output stage, according to the characteristic that the parity check matrix H is a quasi-cyclic shift matrix splicing, the pipeline structure of the RU coding method is simplified, the number of pipeline stages is reduced from six to four, and the coding delay is shortened. At the same time, according to the implementation characteristics of the main functional modules, the maximum pipeline delay is reduced and the encoding throughput is improved. Then, according to the characteristics of the quasi-cyclic shift matrix operation, the resource consumption of the encoder ROM was reduced, and the sparse matrix multiplication vector in the RU method was replaced by the quasi-cyclic shift unit matrix multiplication vector, and the quasi-cyclic shift matrix multiplication vector was used instead of Non-sparse matrix-by-vector in RU methods. In order to meet the requirements of variable code length and variable code rate, the ping-pong RAM between stages can reserve a large storage space.