A new energetic ionic salt bis-1, 2, 4-triazolium 1H, 1′H-5, 5′-bistetrazole-1, 1′-diolate (T₂BTO) was synthesized by using 1H, 1′H-5, 5′-bistetrazole-1, 1′-diol dihydrate (BTO) and 1, 2, 4-triazole as starting materials. Its structure was characterized by X-ray single crystal diffraction, FT-IR, ¹H NMR, ¹³C NMR and elemental analyses. Its thermal behavior was studied by differential scanning calorimetry(DSC) and thermogravimetry-derivative thermogravimetry(TG-DTG). Its kinetic parameters of thermal decomposition(activation energy E_a、E_O and pre-exponential factor A)were calculated by Kissinger′s and Ozawa′s method. The characteristic drop height of impact sensitivity (H₅₀) was determined by WL-1 type impact sensitivity test instrument. Its detonation velocity (D) and detonation pressure (p) were calculated by Kamlet-Jacobs empirical formula. Results show that the crystal of T₂BTO is monoclinic, space group C2/c with crystal parameters of a=15.2410(12) Å, b=10.5185(8) Å, c=7.7546(7) Å, V=1221.26(18) Å ³, ρ=1.688 g·cm^-3, Z=8. Its thermal decomposition temperature on DSC curve at 10 K·min^-1 is 519.9 K, there is only one stage on TG curve with a mass loss of 90.8 % between 453.2 K and 523.2 K, revealing a better thermal stability. E_K=144.39 kJ·mol^-1, E_O=145.52 kJ·mol^-1, ln(A/s^-1)=32.99, H₅₀>61.0 cm, D=7579 m·s^-1, p=24.49 GPa.