5,6-Diaminobenzimidazolone-2 is obtained in an overall yield of 62.1% by nitration of benzimidazolone-2 and followed with hydrogenation. Single-factor experiments were conducted to optimize the reaction condition. 5,6-Dinitrobenzimidazolone-2 was synthesized by Nitration of benzimidazolone-2 under 0℃,8h,n(nitric acid)∶n(benzimidazolone-2)=2.2 in 69% yield. 5,6-Diaminobenzimidazolone-2 was made in absolute alcohol in 90% yield by 8h of Raney-Ni catalytic hydrogenation of 5,6-dinitrobenzimidazolone-2 under the condition of 100℃、2.5MPa、m(catalyst)∶m(5,6-dinitrobenzimidazolone-2)=9%.MS、HPLC、IR、1H-NMR、13C-NMR and elemental analysis are properly used for characterization of the structures of the product.