Abstract: In the paper,the feasibility and conditional tests including feed speed and air pressure of pneumatic milling technology used in ceramic UO 2 powder manufacturing process are studied. The test determines 100～150 kg/h of feed speed and 0.65～0.75 MPa of air pressure as the optimized parameters. The test results show that the pneumatic milling process not only can solve the milling technology with big particle size of UO 2 powder and environment contamination during milling operation, but also can reduce the time of ADU reduction, and the UO 2 powder after reduction by kilning and without stabilizing and sieving can be directly introduced into milling device for pneumatic milling. The UO 2 powder passed the pneumatic milling operation has the better physical and chemical characteristics,and it meets the needs of design specification.