The invention relates to a self-adaptive compression method achieving matching of joint photographic experts group (JPEG) image size upper limits of an intelligent transportation system. The method includes: acquiring parameter information of a source image, calculating an integrated compression quality factor, calculating weighting factors of compression parameters, re-sampling for the source image according to the need, calculating an integrated quantization step factor and revising a standard quantization table to a special quantization table, carrying out ranking and setting up different JPEG coding options, carrying out discrete cosine transformation, scalar quantization processing and Huffman coding to obtain JEPG image information actually input, and storing the information into a self-learning parameter bank. The self-adaptive compression method achieving the matching of the JPEG image size upper limits of the intelligent transportation system achieves automatic compression processing with the upper limits capable of being matched with high-definition JPEG vehicle images to facilitate data storage and transmission, and achieves the purpose of effectively controlling the size and the quality of the images according to the need. The usage is flexible and convenient, the working performance is stable and reliable, and the range of application is relatively wide.