Unilateral　external　fixators　are　widely　used　in　orthopedics　to　stabilize　fractured　bones　and　in　the　treatment　of　limb　deformities.　Vivo　mechanical　environment　inside　and　around　the　fixator　may　influence　the　healing　of　fractured　bone.　Due　to　the　existence　of　pin　deviation　may　affect　biomechanical　environment　of　callus　in　the　fracture　gap.　Finite　element　analysis　was　used　to　investigating　stress　and　deformation　of　fixator-bone　system　under　axial　load,　torsional　load　and　bending　load,　comparing　the　biomechanical　properties　of　two　fixator　structures:　the　one　has　pin　deviation　angle,　the　other　has　no　pin　deviation　angle.　These　results　reveal　that　the　existence　of　pin　deviation　would　affect　the　biomechanical　environment　of　fractured　bone.　When　fixator-bone　system　under　three　kinds　of　load,　the　stress　and　deformation　of　fixator-bone　system　were　greater　than　that　of　fixator-bone　system　without　pin　deviation.　This　work　provides　orthopedics　doctor　useful　information　to　predict　the　micromovements　of　fixator-bone　system.　©　2018　Jianfeng　Li,　et　al.