The invention relates to an intelligent detection system for a cable tunnel. The intelligent detection system comprises a rail assembly, a power supply assembly, a communication assembly, an intelligent detection robot and a monitoring center platform. By means of the system, it can be achieved that the tunnel is repeatedly inspected without a break, it is achieved that the tunnel state is continuously and dynamically collected, and it is ensured that emergency situations in the tunnel are found for the first time. The intelligent inspection robot can enter a cable tunnel accident site where the environment is complicated, and send the data, such as videos and images on the site, the content of harmful gas in air and temperature/humidity alarm, back to a command center, and meanwhile, theintelligent inspection robot can also execute fire suppression, emergency intrusion command and other related disposal measures, so that disaster situations are prevented from spreading for the firsttime, and better disaster prevention and reduction effects are achieved. The intelligent detection system can be sufficiently linked with original on-line monitoring items, various linkage functions of a software platform are given full play to, and the intelligent detection system has the functions of automatic daily inspection, automatic location and re-inspection of outliers, manual control over re-inspection, manual disaster treatment and the like.