How to implement security obstacle avoidance is important to the Mobile Robots. Now the robots become more and more intelligent. How to sense the uncertain surrounding environment and to act directly are basic factors for intelligent robots. But single range-sensor cannot do well to ensure the precision, the quick response and the reliability of measuring data. Multi-sensors are designed for the Range-Measurement System of Mobile Robots based on ARM. The system can fulfill the data acquisition from different sensors simultaneously and process them by the Adaptive Weighted Data Fusion Algorithm. Then it transmits the real-time and precision ranging-data to the upper controller. At last the testing data indicate that the system can improve the range-measurement precision.