Abstract: In order to minimize the waste production in the conventional ammonolysis process of O,O-dimethylphosphorochloridothioate, some source reduction measures were developed，including using O,O-dimethylphosphorochloridothioate instead of benzene as extractant, improving the purity of the starting material O,O-dimethylphosphorochloridothioate，converting conventional batch STR reactor to a recycle tubular reactor，adopting more effective extraction equipment，optimizing operation conditions and using automatic control. At the same time，the wastewater was recycled and ammonia chloride was recovered in the ammonolysis process. These waste minimization measures have been implemented in an industrial process，leading to significantly less waste generation and much lower production cost.