Abstract: To eliminate the reaction runaway of chemical process, the reason for the reaction runaway was analyzed, the assessment methods of reaction runaway and common test technology were introduced. The objective of testing, the selection of test technology, and the meaning of the test results were explained. The process characteristics and main risk of 15 kinds of hazardous process, issued by SAWS, were introduced. The major causes of runaway of each kind of hazardous process were discussed and technical support for the safety control scheme was present. Finally, the specific process control model of phosgenation reaction, as an example, was analyzed.