Taking construction crane for example, this thesis builds a reliable, controllable and easy-to-exploiting CAN-bus application network on the basis of iCAN series functional module and CAN-bus interface card of ZLG system, and it explores the methods of rapid allocation in control networks of construction engine. With CAN-bus controlling devices to guide all signals of sensors and output dates, this system is easily constructing and conveniently stalling. Meanwhile, this system has a good anti-inference ability, a high reliability and a good real-time response. The application of CAN-bus enables lifting moment restriction system to act as a subsystem embedded in other engineering control systems. The construction of this system has an important reference in explore a new generation of engineering control system.