The invention discloses a pepper grinder, which comprises a hollow containing unit, a grinding unit assembled on the bottom of the containing unit and used for grinding pepper, and an opening and closing unit, wherein the grinding unit defines a spilling port positioned on the bottom; and the opening and closing unit comprises an opening and closing element arranged below the grinding unit, the opening and closing element can move up and down and convert between a closing position and an opening position. When on the closing position, the opening and closing element obstructs outside space beyond the spilling port and the pepper grinder, and when on the opening position, the spilling port is communicated with the outside space beyond the pepper grinder; therefore, when the opening and closing unit moves to the closing position to block the spilling port, the pepper grinder can avoid pepper powder left in the grinding unit falling outward after use.