Thermal expansion of explosives have important impact on their applications and investigations on the relationship between thermal expansion and crystal preferred orientation can provide some guide for controlling the shape stability. This paper studied the preferred orientation (F) of 1,3,5-triamino-2,4,6-trinitrobenzene(TATB)crystals using X-ray diffraction and Rietveld refinement, and studied the thermal expansion of die-pressed cylinders with near-spherical, platy and raw materials TATB. Finally, the relationship between the crystals preferred orientation and thermal expansion was investigated. It′s shown that die-pressed TATB cylinders usually take place anisotropic thermal expansion with the coefficient of thermal expansion (CTE) along the diameter about 2 times of that along the radial, and the formula can be pressed as αCTE=(7.08+10.37×F)×10-5K-1. The thermal expansion of TATB cylinders increase with the crystal preferred orientation, and TATB cylinders with different morphological crystals have different preferred orientation. So, we can try to control the preferred orientation by change the crystal morphology, further to restrain the anisotropy of thermal expansion, and finally to improve the shape stability of TATB cylinders. 