Nitrogen-rich fused-ring energetic molecules have gained extensive attention in the field of energetic material due to their high nitrogen content， high enthalpy of formation， and extensive conjugated structures， which enable a better balance between energy and safety. Nevertheless， their synthetic routes are often relatively cumbersome， involving skeleton construction and functional group introduction. In this work， starting from commercially available 4-nitro-1H-pyrazole-3，5-diamine and sodium nitromalonaldehyde， the fused bicyclic energetic molecule 2-amino-3，6-dinitropyrazolo［1，5-a］pyrimidine （1） was synthesized in a one-step reaction with a high yield of 89.3%. The target compound was characterized by nuclear magnetic resonance， infrared spectroscopy， and single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with a measured density of 1.774 g·cm^-3 at room temperature. Its detonation performance was calculated by EXPLO5 software， its thermal decomposition temperature and mechanical sensitivity were evaluated by thermogravimetry-differential scanning calorimetry and impact/friction sensitivity tests. The results indicates that compound 1 possesses an onset decomposition temperature of 303 ℃， based on measured density， a calculated detonation velocity of 7680 m·s^-1， and a detonation pressure of 22.7 GPa. Its impact sensitivity is better than 60 J， and friction sensitivity is greater than 360 N， demonstrating that it is a thermally stable and insensitive explosive molecule with potential application value.