This system through the man-machine interaction interface and various signal sensors，can real-time reflect the arm angle, height, working amplitude, lifting weight, load and other information of the excavator to the operator,make the operating capacity of the excavator is safe and effective in the range of design parameters. When the excavator operation is close to or beyond the safe range.The host computer will send sound and light alarm to remind the operator to stop the illegal operation,if the operator continues to violate the rules,the host computer will send auto lock signal and stop the arm of the excavator to dangerous direction,so as to avoid the safety accident of excavator and operator effectively.