Using acetone as solvent, the process conditions of preparing the spherical HMX by spray drying method were optimized by the orthogonal test L₉(3⁴), and the spherical HMX obtained under the optimal condition was characterized by scanning electron microscope (SEM). The morphology of the obtained HMX was quantitatively analyzed by the scoring method. Results show that the optimal preparation conditions of the spherical HMX are inlet temperature of 70 ℃, feed rate of 1.5 mL·min^-1, spraying gas flow rate of 473 L·h^-1, mass fraction of 1.5%. The median particle size of the spherical HMX obtained under optimal experimental conditions is 997.56nm and the crystalline form is the β type. Compared with raw HMX, the characteristic drop height of impact sensitivity for spherical HMX is increased by 28.21 cm.