A novel energetic salt of diaminoglyoxinium 1H, 1′H-5, 5′-bitetrazole-1, 1′-diolate (DAGBTO) was synthesized by using diaminoglyoxime(DAG) and 1H, 1′H-5, 5′-bitetrazole-1, 1′-diol(BTO) as raw materials, and its structure was characterized by elemental analysis, Fourier transform infrared spectroscopy(FT-IR) spectroscopy, ¹H NMR, ¹³C NMR and mass spectrometry. The single crystal of DAGBTO was obtained and its structure was determined by X-ray single-crystal diffractometer. Results show that DAGBTO belongs to monoclinic space group C2/c with a density of 1.782 g·cm^-3, and the cell parameters are as follows: a=11.3121(11) Å, b=6.4480(4) Å, c=15.3202(16) Å, β=105.990(2) °, V=1074.23(17) ų, F(000)=592. The thermal decomposition behavior was investigated by differential scanning calorimetry(DSC) technology, and non-isothermal kinetic parameters were also calculated. Results indicate that it has a good thermal stability with the decomposition temperature above 190 ℃. The apparent activation energy are 210.6 kJ·mol^-1 (Kissinger) and 207.9 kJ·mol^-1(Ozawa-Doyle), respectively, and the critical temperature of thermal explosion is 200.7 ℃.