A knitting machine includes a base unit, a plurality of transmission mechanisms, a plurality of spool stands, a collecting mechanism, a driving device and a microcomputer control unit. Each of the transmission mechanisms includes a plurality of driving gears and a plurality of blades. Each of the spool stands is provided with a spool. The collecting mechanism includes a plurality of hubs each provided with a convergent holding device. When the transmission mechanisms are driven, the spool of each of the spool stands is disposed at an operation state. The collecting mechanism collects and guides the lines of the spool of each of the spool stands to perform a knitting work so as to form rope belts. Thus, the rope belts present a thick-and-thin alternating mode, a multi-layer mode or a three-dimensional mode.