The describing format of the folding pattern was analyzed. The folding pattern was decomposed according to the relative location relationship and direction changing character of folds, on which the complicated folding pattern was decomposed as a combination of a series of ordinal parallel folding patterns. Combined with the parallel folding patterns, the matching relationships between folding patterns and folding units were studied, and the matching rules of folding patterns and folding units were induced. Using the 85 folding patterns defined by JDF as reference, a working ability analysis method of folding machine based on the matching relationship between folding pattern and folding unit was put forward.