The large smooth ε-CL-20 particle was prepared by adding CL-20 filtrate to anti-solvent, precipitated a small amount of crystal of playing a similar role of seed crystal, and the secondary faster adding a lot of anti-solvents, made the crystal grow along the seed crystal. The effect of solvent volume and stirring rate on the morphology and size of ε-CL-20 was analyzed. The performances of ε-CL-20 after crystallization were characterized. Results show that compared with the raw material, the crystal particles of ε-CL-20 prepared by this method have the characteristics of smooth surface, no sharp edge angle, high density and narrow size distribution. The characteristic drop height H₅₀ of ε-CL-20 increases from 25 cm to 40 cm, the friction sensitivity decreases from 96% to 32%, the density increases from 2.0367 g·cm^-3 to 2.0384 g·cm^-3.