Hazardous chemicals have their own intrinsic properties such as explosive, flammable, corrosive, toxicity, and radioactivity, which will lead to great threats and substantial security risks in the transportation, application and storage processes. Problems, if possibly arisen in the transportation and management processes, may cause a major accident. We have to fight through some troubles in the whole process. For this purpose, the paper designs and implements a chemical logistics supervision and forewarning system based on the Internet of Things (IoT) cloud computing, which integrates IoT technology to collect, merge and transmit geographical location information and operation conditions for chemical supply chain such as storage and distribution, environmental parameters for hazardous chemicals, monitor and analyze the transportation route safety and driver operation status. This is a real-time surveillance over the whole logistics chain for hazardous chemicals. Here analyze and aggregate the parameter thresholds of the feature elements that lead the hazardous chemicals logistics to accidents. When the platform detects there is a parameter that reaches the critical threshold, the system automatically issues a warning signal according to the preset forewarning decision program, and then takes measures for level-to-level troubleshooting against it, thereby realizing the monitoring and forewarning on the hazardous chemicals logistics. It is proved by the test that the function modules on the platform all fill the bill for the design and implementation. Given the above, this platform can well apply to monitoring and early warning for hazardous chemicals logistics.