To study the effect of recrystallization process on fhe thermal properties and mechanical sensitivity of dihydroxylammonium 5, 5′-bistetrazole-1, 1′-diolate(HATO, TKX-50), Six kinds of HATO samples with different particle size and morphology were prepared using falling temperature method and solvent-nonsolvent method respectively. The particle size and morphology of HATO samples obtained by different recrystallization process were characterized by laser granularity instrument and scanning electron microscope(SEM). The thermal decomposition properties was analyzed by means of differential scanning calorimeter(DSC). Its impact and friction sensitivities were were measured by GJB772A-97 method. The results show that HATO samples without addition of surfactnt obtained by falling temperature method have maximum particle sizes(d₅₀=196.5 μm), the crystal surface is smooth and the shape is regular, showing the highest decomposition temperature and the lowest mechanical sensitivity. Its decomposition peak is 249.1 ℃. The impact and friction sensitivities are 8% and 20% respectively.