A novel nonmetallic salt， 3，5，7-triamino［1，2，4］triazolo［4，3-a］［1，3，5］triazine pentazolate （4）， was synthesized through a metathesis reaction by employing AgN₅ as precusor with 3，5，7-triamino［1，2，4］triazolo［4，3-a］［1，3，5］triazine hydrochloride. The structural characterization were carried out by X-ray single crystal diffraction， infrared spectroscopy （IR）， elemental analysis （EA）， nuclear magnetic resonance （NMR）， and thermal decomposition behavior were determined by thermogravimetric analysis （TG） and differential scanning calorimetry （DSC）. The enthalpy of formation of compound 4 was calculated using atomization method， the detonation performance was predicted using EXPLO5， and sensitivity was tested using BAM testing method. The results show that compound 4 exhibits a monoclinic crystal structure with a crystal density of 1.644 g·cm^-3 and belongs to the P2₁/n space group. This compound has a nitrogen content of 77%， a thermal decomposition temperature of 113.8 ℃， and an enthalpy of formation of 491.5 kJ·mol^-1. Furthermore， its detonation velocity was calculated at 7913 m·s^-1， detonation pressure at 19.6 GPa； The impact sensitivities measured were >40 J， and friction sensitivity >360 N.