To gain insights into the stability of nano TATB in different storage environments， aging conditions at 90 ℃， 10%RH， 50%RH， 90%RH and 200 Pa low atmospheric pressure were considered. The microstructure evolution of nano TATB was characterized by small angel neutron scattering （SANS）， scanning electron microscope （SEM）， X-ray diffraction （XRD）， Raman spectroscopy （Raman） and infrared spectroscopy （IR）. Results show that the specific surface area of nano TATB decreases obviously after the thermal aging at 45 ℃， 60 ℃ and 71 ℃， and the higher the aging temperature， the more obvious the specific surface area decreases， accompanied by the growth of some crystal particles. The long-term stability of nano TATB crystal particles is significantly affected by the extreme humidity and heat environment （90 ℃， 90% RH）. After short-term storage （5 days）， the nano TATB particles grow up with the size of about 1-3 μm. The nano TATB particles also grow and form a micro flake structure after aging in a low pressure （200 Pa） environment at 90 ℃. Based on the experiment results， the growth and aging mechanism of nano TATB were discussed. The high surface energy of nano TATB facilitates TATB molecules overcoming the energy barrier， which results in the TATB molecules diffusion and rearrangement on the crystal surface and correspondingly leads to the grow-up of particles.