1. A decoding method for a low-density parity-check (LDPC) code, comprising:dividing, by a decoder, an LDPC code C whose bit length is n into k divided LDPC codes D, the LDPC code C={c1,c2,c3,K,cn-1,cn}, the divided LDPC codes D={D1,D2,K,Dk-1,Dk}, Di={c(i-1)l+1,c(i-1)l+2,K,cil-1,cil}i=1,2,K,k?1,k, and a bit length of the Di comprising l=n/k;

arranging, by the decoder, the Di,i=1,2,K,k?1,k by column to obtain transpose codes (DT) of the divided LDPC codes D, the DT={D1T,D2T,K,Dk-1T,DkT}, DiT={c(i-1)l+1,c(i-1)l+2,K,cil-1,cil}T, and i=1,2,K,k?1,k;

performing, by the decoder, cyclic shift on the DiT,i=1,2,K,k?1,k by row according to values of corresponding elements in a target check matrix to obtain shift codes (E), the E={E1,E2,K,Et-1,Et}, t being equal to a quantity of rows of the target check matrix, Ej comprising a result of shifting the DT according to an element of a jth row in the target check matrix, and j=1,2,K,t?1,t;

obtaining, by the decoder, t*m groups of LDPC subcodes according to the E and a bit length of the decoder (d), the LDPC subcodes comprising F1,F2,K,Ftm-1,Ftm, the Ej being divided into m groups, the Ej={(Ej)1d,(Ej)d+12d,K,(Ej)(m-2)d+1(m-1)d,(Ej)(m-1)d+1md}={F(j-1)m+1,F(j-1)m+2,K,Fjm-1,Fjm}, (Ej)(s-1)d+1sd, s=1,2,K, m?1,m denoting an [(s?1)d+1]th row to an (sd)th row of the Ej, and m=?l/d?; and

decoding, by the decoder, m groups of the LDPC subcodes to obtain a decoding result of the LDPC code C such that a quantity of parallel decoding operations on the LDPC code C being controlled flexibly.