The embodiments of the present invention provide an encoding and decoding method and device. The encoding method includes: equally dividing input K-bit information into n blocks, where k1, k2, . . . , and kn are used to represent each block of information; combining a kith block of information with n−1 encoded code words Vi−1, Vi−2, . . . , and Vi−n+1 of ki−1th, ki−2th, . . . , and ki−n+1th blocks, to obtain a code word to be encoded, where when a sequence number of an encoded code word is smaller than or equal to 0, the encoded code word is history information; performing, by using an LDPC check matrix, encoding on the code word to be encoded, where a generated check bit and the kith block of information form an encoded code word Vi; and outputting encoded code words V1, V2, . . . , and Vn. The embodiments of the present invention are applied in encoding and decoding.