Lossless data compression method based on LZ77, error code repair method, encoder and decoder

The invention relates to a lossless data compression method based on LZ77, an error code repair method, an encoder and a decoder. The compression method comprises the steps of: reading to-be-compressed character strings, and acquiring an encoded symbol sequence and to-be-encoded character strings; according to a sliding window parsing sequence, sequentially searching and recording longest matchingprefixes of a current to-be-encoded character string from the encoded symbol sequence; according to the matching multiplicity of the longest matching prefixes of the current to-be-encoded character string, determining embedded bit information; carrying out mapping on the embedded bit information and each longest matching prefix of the current to-be-encoded character string one by one; and according to a preset embedding value, selecting the corresponding longest matching prefix as a code word of the current to-be-encoded character string, outputting the code word, and until the code words ofall the to-be-encoded char