The invention discloses a hexazinone cleaning production technology. According to the technology, ethanol, lime nitrogen, cyclohexylamine, dimethylamine, dimethyl sulfate, sodium and phosgene are taken as main raw materials, a series of chemical reactions are carried out in a solvent, and then desolventizing and concentrating, crystallization separation and drying are carried out so as to obtain afinished product of hexazinone. The technology has the advantages that solvent extraction is omitted, the reaction process is reduced, the efficiency is improved, the energy consumption is saved by 10%, and meanwhile, the conversion rate is increased by 5%; the waste water quantity is greatly decreased, a special reactor is used in the cyclization process, the use of dimethylamine is reduced, sothat the phenomenon that great troubles are brought to removal of dimethylamine in the solvent and recovery of the solvent due to the fact that dimethylamine is dissolved in the solvent can be avoided, the severe pollution of dimethylamine to the environment is reduced, the quality of the solvent is guaranteed, and the content of active compounds of hexazinone is qualified, namely, the content ofthe active compounds of hexazinone is greater than or equal to 98%; and the use of a lot of water and dimethylamine is saved, so that the production cost is greatly lowered.