The invention relates to a plant mill, which comprises a bottom frame, and a three-phase asynchronous motor and a crushing chamber fixed at the bottom frame, wherein the crushing chamber is internally provided with a spindle; fine crushing knives are fixed on the spindle; the spindle and the three-phase asynchronous motor are connected via a rubber belt; the plurality of fine crushing knives are irregularly or regularly connected in series onto the spindle; each fine crushing knife is provided with a superalloy blade; and the crushing chamber is internally provided with an inner cylinder for rebound of broken plant particles. The plant mill has the beneficial effects that the inner cylinder and a rack body are matched for realizing strong rebound of medicine particles so as to quicken the crushing efficiency, the superalloy blades are matched for realizing high-efficiency medicine crushing, and thus high temperature during the crushing process is low and time is shortened; the time of the crushing process is short, thereby saving electric energy and reducing wear; a locking ring is used for locking the fine crushing knife, thereby reducing vibration in the case of crushing; and as a feed inlet is located above a cover plate, the best medicine entering position is provided, and the crushing effects are enhanced.