In order to study the properties of 2,6-diamino-3,5-dinitropyridine-1-oxide (ANPyO), the three refined samples of ANPyO were prepared by recrystallization from the solvents of trifluoroacetic acid(CF₃COOH), dimethyl sulfoxide(DMSO) and N,N-dimethyl formamide(DMF) respectively, and the properties of the three samples were compared. Results show that the particle size of ANPyO prepared by recrystallization from CF₃COOH distributes from 2 μm to 70 μm and its BET specific surface area is 0.454 m²·g^-1. The differential scanning calorimetry (DSC) analysis and thermal decomposition kinetics calculation show that, compared with ANPyO prepared by recrystallization from DMSO and DMF, enthalpy of decomposition of ANPyO（CF₃COOH） is 1021.46 J·g^-1, and the temperature of the exothermic peak is 370.69 ℃, and its activation energy is 279.63 kJ·mol^-1 at a heating rate of 10 K·min^-1. Impact and friction sensitivity of ANPyO prepared by recrystallization from CF₃COOH are 20% and 18%, respectively.