Intelligent Distribution system of tunnel is an important part of Intelligent transportation system of expressway, and a safe and reliable distribution system is the foundation to ensure the safe operation of tunnel. On the basis of researching the intelligent hardware products that can be applied in the market, the application of Schneider Electric"s intelligent power distribution system in tunnel project of G98 expressway all-around in Sanya Yazhou Bay is taken as an example. By analyzing the problems of traditional distribution system in tunnel and combining with the actual characteristics of daily management and operation and maintenance of tunnel, the overall architecture of the intelligent distribution system is described, how to build intelligent power distribution system in engineering is discussed. The intelligent and optimized of operation and maintenance management is realized to ensure the safe, efficient, sustainable and healthy development of the tunnel