Abstract: The highly reliability CAN-bus network node composed of microprocessor, CAN-bus driver and expand interfaces is designed. CPU and CAN controllers are integrated into a single chip. This paper not only propose the circuit design of the CAN-bus network node system, and also develop the application software on RTX51 Tiny, a real-time operating system (RTOS), running in this node system. Finally, Verilog and C codes are verified by FPGA's IDE tools, and tested in the node, a FPGA board. Actual operation results show that the node system function is trustworthy, and the software system is reliable.