Intelligent Circuit Breaker is a new sort of Circuit Breakers, which includes computer technology, digital processing technology, and communication technology. The design of intelligent circuit breaker controller is completed by using the MSP430 MCU of TI Company. Besides the essential three kinds of LCD display, safeguard functions, the intelligent circuit breaker controller has the characteristics of heat-memory and self-diagnosis. By applying field bus technology, the data and the control information can be transferred through CAN bus. The principle of hardware systems and the concrete circuits are offered, and the design of software is explained in this paper. Intelligent circuit breaker is a new sort of Circuit Breakers, which includes computer technology, digital processing technology, and communication technology. The design of intelligent circuit breaker controller is completed by using the MSP430 MCU of TI Company. , safeguard functions, the intelligent circuit breaker controller has the characteristics of heat-memory and self-diagnosis. By applying field bus technology, the data and the control information can be transferred through CAN bus. The principle of hardware systems and the concrete circuits are offered, and the design of software is explained in this paper.