One kind of pepper grinder grinding unidirectional structure. In the pepper grinder housing pivoted shaft, solid shaft located inside the bottom of the grinding wheel, grinding wheel peripheral units located within a housing fixed on the outer grinding ring, shaft sleeve solid unidirectional device housing pivoted lever in order to cooperate with moving structures to promote unidirectional device, pressing operation lever, it will make even the moving structure driven by unidirectional device uninterrupted continuous rotation; this structure has a grinding speed grinding and polishing effect is good and so is the way to use better performance of the one-way grind pepper mill structure.