To obtain the solvent-free single crystal of 3, 4-dinitropyrazole (DNP) structure, DNP was synthesized by a 3-step method using pyrazole as raw material. The single crystal of DNP was cultured by solvent evaporation method using ether as solvent. Its single crystal structure was determined by a X-ray single-crystal diffractometer. Results show that the crystal is monoclinic, space group is P2₁/c, with cell parameters of a=9.9801(8)Å, b=11.9959(9)Å, c=9.7192(7)Å, β=94.232(1)°, V=1160.41(15)ų, F(000)= 640, Z=8, D_c=1.80969 g·cm^-3.The existence of numerous intermolecular hydrogen bonds and the π-π stacking interaction existed between the DNP molecules make the DNP molecules stably exist.