A series of Zn0.99Fe0.01O bulk samples were synthesized by a solid-state reaction method combined with high-pressure treatment technique. The effect of high pressure on the structure and magnetic properties of the sample was investigated. It was found that the lattice constants a and c of Zn0.99Fe0.01O decreased gradually with the increase of treatment pressure from 0 to 5 GPa, and the particle size of Zn0.99Fe0.01O increased markedly with the increase of treatment pressure. All samples presented obvious ferromagnetic behaviors at room temperature, and it was proved that the ferromagnetism was enhanced significantly with the increase of the treatment pressure.