The present invention relates to the crystalline amoxicillin trihydrate powder of bulk density greater than 0.45g/ml.The invention still further relates to a kind of method for preparing crystalline amoxicillin trihydrate powder, described method comprises: crystallization goes out amoxicillin trihydrate from the solution that contains dissolved amoxicillin From described solution, isolate crystal With dry isolating crystal, obtain the crystalline powder of bulk density greater than 0.45g/ml.
