In an uncertain environment, real-time obstacle avoidance is key technology for a intelligent robot to work autonomously. Sensitive skin endows intelligent robot carrier with an ability to sense surrounding and the ability of real-time decision. The developed robotics sensitive skin is a large-area, flexible, mini-type array of infrared sensors with dataprocessing capabilities, which can be used to cover the surface of robot. Depending on the array of infrared sensors, it endows robot carrier with an ability to sense its surrounding. Distance between sensitive skin and obstacle is measured by using geometric optics model. Experimental results show that the sensitive skin can real-timely provide existence and distance information about obstacles for multi-joint robot within sensory area. The development of the sensitive skin means an attempt in sensing and control. It presents a new paradigm in solving problems such as obstacle avoidance for multi-joint robot. It will promote the development of robot and related science in our country and improve intelligent level. This will be of far-reaching significance to the promotion of robot and will have a wide application and promising prospect.