Abstract: In this experiment, our group studied the preparation methods of inertial confinement fusion polymer microcapsules, and designed a T-junction structure based on dual microchannel device, which was used for the preparation of stable double-emulsion. A glass capillary tube was chosen as the microchannel of middle phase solution, which increased velocity regulation range of three phase solutions, and broadened the size of emulsions. Because of the tiny discrepancy among three phase solutions, the concentricity of the double emulsions improved automatically. Various speeds of solidification were regulated, and the concentricity of the microspheres was optimized under 55 r/min, which was more than 98.7%. Scanning electron microscopy morphology and energy dispersive spectroscopy of dried pellet show that the supercritical drying meets the requirements to remove internal solvent and keeps the pellet structure from destruction. Finally, polyacrylonitrile hollow microcapsules with a size of 300-1000 m and a shell thickness of 20-300 m were successfully fabricated.