A pill grinder and a method for using thereof are provided. The pill grinder includes: a base plate; a guiding assembly; a handle component including a pair of handle connecting rods, wherein, a first connecting rod is connected to a first end of each handle connecting rod, a roller shaft is connected between the handle connecting rods, axial directions of the roller shaft and the first connecting rod are both parallel to a first direction, the first connecting rod is kept pressed towards the base plate by an elastic returning component; and a grinding component, sleeved outside the roller shaft. When the handle component rotates around the first connecting rod, guided by the guiding assembly, the grinding component has a grinding stroke along a second direction perpendicular to the first direction. Therefore, pills can be better grinded with easier operation and less time, and safety in use is largely enhanced.