Abstract: In consideration of the technology features of knitgoods heat setting machine and the synchronization control problem of conventional speed governing device,a speed regulating system based on CAN bus and Lenze frequency-conversion was developed.The all digital field bus control by the PLC to the drive system with the transducer was realized.The synchronous control demands of the speed chain were satisfied.This solution highlights the structure and chief functions of the leading drive speed regulating system.The block diagram of hardware and software for the system was presented.The control objectives of the system have been achieved by design and debugging.