In the synthesis of diazepam,ammonium bicarbonate,ammonium carbonate and HA were compared respectively,and the effect and yield of ammonium bicarbonate cyclic in diazepam synthesis were better.In further experiments,the optimal syn-thesis conditions were found by adjusting the mass ratio,reaction temperature and reaction time of 2-(N-methyl-chloroacetamide)-5-chlorobenzbenone and ammonium bicarbonate.The results showed that the reaction temperature of 52℃and the reaction time of 7 h had a significant effect on the synthesis yield of diazepam,with the highest mass yield of diazepam when 2-(N-methyl-chloro-acetyl)-5-chlorophenone and ammonium bicarbonate was 1∶6.In the resulting reliability validation experiment,three replicate ex-periments were performed with synthetic yields of 84.8%,84.7%and 84.9%,which further showed that the yield of synthetic diaze-pam was relatively stable and reliable under this process condition.