OBJECTIVE： To optimize the preparation technology of Angelica sinensis powder and conduct screening for the optimal particle size thereof. METHODS： With the contents of volatile oil and ferulic acid as the indexes， screening was conducted for the optimal drying temperature， dry welding time and particle size of the crude drug A. sinensis， and the stabilities of the A. sinensis powder with different particle sizes which was packed by simulating that sold in the market were investigated. The verification tests on the preparation technology were conducted. RESULTS： The optimal conditions for preparing the crude drug A. sinensis were as follows as drying temperature of 60-70 ℃， drying for 4.5-5 hours and being crushed into moderate-sized powder； the stability of the moderate-sized powder which was packed by simulating that sold in the market was the best. In the verification tests on the preparation technology， the average content of the volatile oil was 0.46 ml/g， with RSD of 0.034％ （n＝3）； the average content of the ferulic acid was 0.123 μg/ml， with RSD of 0.026％ （n＝3）. CONCLUSIONS： The optimized technology is stable and feasible， and the stability of the moderate-sized A. sinensis powder is the best.