The attachment energy （AE） model and molecular dynamics （MD） methods were used to predict the crystal morphology of 1，1-diamino-2，2-dinitroethylene （FOX-7） under vacuum condition and in eight solvent systems including dimethylsulfoxide （DMSO）， acetone， methanol， N-methylpyrrolidone （NMP）， N，N-Dimethylacetamide （DMAC）， ethylacetate （EA）， water （H₂O）， and DMSO/H₂O （V/V=2/1）. By calculating the interaction energies between the solvent and crystal plane， and the attachment energies under the influence of the solvent， the simulated crystal habit and its aspect ratio were obtained. The results show that FOX-7 crystal has six important growth planes under vacuum： （1 0 ）， （1 0 1）， （0 1 1）， （0 0 2）， （1 1 0）， （1 1 ）. Among them， the area of （0 1 1） plane accounts for the largest proportion， which is the most important crystal plane affecting the crystal morphology of FOX-7. The influence degree of solvent on the aspect ratio of crystal is in the following order： DMSO2O2O. By recrystallization experiments， FOX-7 crystals have a bulk-like shape in DMSO， methanol， and DMSO/H₂O； a rod-like shape in acetone and NMP； a needle-like shape in DMAC and H₂O； a flake-like shape in EA. The theoretical prediction results are in good agreement with the experimental results， which proves that the simulation of the crystal habit of FOX-7 based on the AE model can provide better guidance for the crystallization experiment. Results in thermal properties show that the crystal surface morphology and internal defects affect the phase transition temperature and thermal decomposition temperature of FOX-7. The fewer the crystal defects， the higher the α→β transformation temperature. The larger the crystal aspect ratio， the smaller the particle size， and the lower the first decomposition temperature.