Data compression method and data decompression device

The invention is suitable for the field of data compression, and provides a data compression method and a data decompression device. The data compression method comprises the following steps that to-be-compressed data are received; the received to-be-compressed data are divided into a first part of data and a second part of data, and the first part of data serve as a dynamic dictionary for compressing the second part of data; the second part of data are matched with the dynamic dictionary, if matching is successful, the to-be-compressed data are converted into data with a format corresponding to successful matching, and if matching fails, the format of the second part of data is analyzed, and the second part of data with the analyzed format and having a repeat property are converted into data with a format corresponding to failed matching; the dynamic dictionary is updated; compressed data are output. The data compression method and the data decompression device can guarantee high-efficiency compression and achieve efficient compression performance.