A novel energetic potassium salt 2,3,5,6-tetranitro-4H,9H-dipyrazolo [1,5-a:5'',1''-d][1,3,5] triazinane (KTNDPT) was synthesized using sodium 4-amino-3,5-dinitropyrazolate as raw material, and structurally characterized by elemental analysis, IR spectra, ¹H NMR, ¹³C NMR. The single crystal of KTNDPT was obtained and analyzed by single-crystal X-ray diffraction. The thermal behavior of KTNDPT was studied by DSC-TG method. Solid phase formation heat and density were calculated by Gaussian 09 program and Trouton′s rule, and the physicochemical detonation properties of AFTF were predicted by means of EXPLO5 detonation software. The results show that the crystal of KTNDPT·H₂O belongs to a monoclinic system and space group P2₁/n with cell parameters: a=8.330(15), b=9.869(17), c=16.61(3)Å, β=102.04(3)°, V=1335(4) ų, Z=4, D_c=1.966 g/cm³, F(000)=792, μ=0.480 mm^-1, S=1.040, the final R= 0.1541 and wR(I> 2σ(I))=0.3779. DSC-TG analysis shows that the decomposition peak temperature of KTNDPT is 241.6 ℃.The heat of formation is 331.6 kJ/mol, detonation velocity is 8647 m·s^-1 and detonation pressure is 32.0 GPa. As an energetic ion potassium salt, KTNDPT with excellent detonation performance is expected to use in high energy propellants.