To obtain nano-1, 3, 5-triamino-2, 4, 6-trinitrobenzene(TATB) with controllable particle size and higher purity, nano-TATB was prepared by a spraying recrystallization method with trifluoromethanesulfonic acid as solvent and deionized water as non-solvent. The influence of preparation technology and pH on the particle size and purity of nano-TATB was studied. The morphology, specific surface area, crystal structure, purity and thermal decomposition characteristics of nano-TATB were characterized by field emission scanning electron microscopy(FE-SEM), BET(brunauer-emmett-teller) specific surface area test, high performance liquid chromatography(HPLC) and differential scanning calorimetry(DSC), etc. Results show that the volume ratio of solvent to non-solvent can affect the morphology and particle size of nano-TATB. With the decreasing volume ratio of solvent to non-solvent, the particle size of the sample becomes smaller and the size distribution is more uniform. Under the condition of volume ratio 1:50 and pH=7, nano-TATB particles with the size of 60 nm, uniform particles and specific surface area of 31.6 m²·g^-1 are obtained. The effect of pH value on the purity of nano-TATB is very important, with water washing to pH=7, the purity of the sample can reach 98.1%.