According to the demand that the robot can replace the firefighters in the fire scene prone to explosion, such as chemical park or coal industry unit, the autonomous fire source search and intelligent fire-fighting technology of fire robot is studied. Firstly, based on the introduction of the structure and control system of fire-fighting robot, the technical requirements for fire-fighting robot to find fire source autonomously and to extinguish fire intelligently in unknown environment were clarified; Secondly, the working environment of fire robot was analyzed, and the technical scheme of this robot’s looking for fire source and extinguishing fire was put forward; Then, based on SLAM(Simultaneous Localization and Mapping) technology, the fire-fighting robot can walk and avoid obstacles in unknown environment, and the methods and technologies suitable for the robot to find the fire source and to determine its direction were developed; Finally, the effectiveness of the proposed technology on this robot’s finding and extinguishing the fire source was verified by simulation and experiments. The experimental results show that the fire-fighting robot can walk and cross obstacles autonomously in an unknown environment based on this developed technology, and find and extinguish fire source intelligently. It has a positioning accuracy less than 0.4m, a fire source identification rate greater than 90%, and a good application prospect.