The invention discloses a first-order difference prefix notation coding method for the lossless compression of image data, which comprises the following steps of: 1, pre-processing original image data to obtain first-order differences between adjacent pixel values; 2, counting the probabilities of occurrence of each first-order difference, and re-sequencing the first-order differences from higher probabilities to lower probabilities to obtain new first-order differences; 3, performing first-order difference prefix notation coding processing on the new first-order differences obtained by the step 2 to obtain a prefix code table and a suffix code table; 4, performing order-reduction processing on suffix codes in the step 3 by adopting a suffix derivation method; and 5, performing coding processing on primary prefix codes in the step 4 according to bit planes by adopting dichotomy. The method ensures relatively lower computational complexity, simple coding, high coding and decoding efficiency remarkably higher than that of JPEG2000, and no need of adopting special compression and decompression chips, and compared with a conventional lossless compression algorithm, remarkably increases a compression ratio to be equivalent to that of the international standard JPEG2000.