In the preparation of new heat-resisting energetic materials, two new polynitroazobenzene energetic compounds,2,2′,4,4′,6,6′-hexachloro-3,3′,5,5′-tetranitroazobenzene (HCTNAB) and 4,4′-dichloro-2,2′,3,3′,5,5′-hexanitro-6,6′-dimethoxy- azobenzene (DCHNDOCAB), were prepared and their structures were determined by elemental analyses, FTIR, single-crystal X-ray diffraction analysis. Meanwhile, the thermal decomposition temperature was determined by differential scanning calorimetry (DSC) and TG-DTG, the thermal decomposition temperature of HCTNAB is 266.8 ℃, and the thermal decomposition temperature of DCHNDOCAB is 269 ℃. To accomplish the performance prediction of DCHNDOCAB, we used the calculations that based upon the B3LYP (Becke three-parameter Lee-Yang-Parr)/6-311++G^** method gain optimized structure using Gaussian 09. Our research shows that HCTNAB can be seen as a vital energetic intermediate containing active chlorine. The calculated detonation velocity of DCHNDOCAB is 7117 m·s^-1, and the detonation pressure is 21.0 GPa, show that the DCHNDOCAB is hopeful to become a new heat-resisting azo aromatic energetic materials.