The preparation process and determination method of modafinil capsules were studied. By prescription screening and process optimization, the modafinil capsules were prepared and determined by HPLC, and the dissolution was tested. Through prescription screening and optimization, the load difference, dissolution, and other indicators met the quality requirement of the capsules. Modafinil was linear at 200-600 μg·mL-1 (r=0.999 9), the average recovery was 101.4% and RSD was 0.023%. The dissolution of 3 batches of capsules met the requirement. The capsule formulation process is feasible, and the detection method can be used as a quality control standard for modafinil capsules.