The single and double system computer flat knitting machine adopts digital technology, which can realize the turning of needles, hole picking, eye hanging, intarsia, jacquard without dotted line, four-level jacquard, open and dark narrowing, and other regular patterns of flat knitting machines. Before starting weaving, it can automatically scan the weaving files and select a system suitable for the pattern, so as to truly provide fast rotation of the nose, high speed and high efficiency.