To investigate the preparation and factors of the release mechanism of Indomethacin sustained release micro-pill capsules. The results showed that: successfully prepared indomethacin sustained release capsules after investigation of various influence factors with stable quality. The formulation of microcrystalline and starch and Polyacrylic Resin II showed marked effects on the quality of micro-pill. A proportion between Et cellulose and Polyacrylic Resin II and the increasing of the coating weight are the main factors affecting drug release. The process conditionings of indomethacin sustained release capsules is stable, reached steady release speed in 12 h.