A rhythmic pill crusher, including: a crushing cover including a cylindrical boss, wherein a plurality of first threads formed on a first wall of the crushing cover and around a column portion of the cylindrical boss, wherein the first wall is distant from the column portion of the cylindrical boss; and a supporting platform including a cylindrical recess for receiving the cylindrical boss and a plurality of second threads formed, in response to the first threads, on a second wall of the supporting platform; wherein the first threads are loosing engaged with the second threads, the first threads spirally go upward and downward along the second threads, or the first threads suspend relative to the second threads, which allows the first threads to rotates remaining in a same height. The pill crusher can be operated efficiently and easily and can be cleaned easily for reducing cross contaminations.