It is indispensable that that intelligent robots boast mobile operation and obstacle avoidance as the main technology. A mobile obstacle avoidance system of intelligent robots is developed, with ultrasonic sensor and single chip microcomputer(MCU) control as the main technology, supported by Camel machine rotation, motor drive and power supply modules. The test results show that the control of steering engine rotation enables the sensor to detect flexibly obstacles from multiple positions, with a good obstacle avoidance performance to make sure the robot runs safely and stably, thus providing an effective means for the obstacle avoidance technology of intelligent robots.