2, 6-Diamino-3, 5-dinitropyrazine (ANPZ) is an important insensitive high explosive of pyrazine type. To further understand the crystal structural characteristics of ANPZ, we employed terahertz time-domain spectroscopy (THz-TDS) to study the spectral evolution of ANPZ from 24 ℃ to 150 ℃. The solid-state density functional theory (DFT) was adopted to calculate and analyze the THz vibration characteristics of ANPZ. The results show that ANPZ has obvious absorption from 0.3 THz to 2.1 THz and its vibration mode originates from the interaction between the nitro groups and adjacent atoms, which is helpful for the understanding of ANPZ structures and the design of new derivatives. Moreover, the absorption at 1.14 THz and 1.92 THz shows different evolution characteristics as the temperature rises, which suggests that the interaction between the two nitro groups of ANPZ and surrounding atoms responds differently to thermal stimuli. Our results can guide the comprehension of the physical mechanism for ANPZ under high-temperature loading and even final combustion or explosion.