The　main　purpose　of　this　research　is　to　perform　a　magnetic　analysis　on　magnetic　equipment　of　permanent　magnet　retarder　(PMR)　and　optimize　the　structure　of　magnetic　equipment　with　ANSYS,　finite　element　analysis　software　and　its　design　optimization　module.　The　physical　model　is　built　as　axisymmetric　model　according　to　the　characteristics　of　the　structure　in　magnetic　equipment.　Using　this　model,　the　magnetic　field　distribution　and　magnetic　force　is　calculated　by　ANSYS.　Mathematical　model　of　structure　optimization　is　also　built.　The　design　variables　are　structural　parameters　including　the　dimensions　of　permanent　magnets　and　magnetic　yoke;　the　objective　function　is　the　magnetic　force.　The　unconstrained　optimization　model　takes　the　maximum　value　of　magnetic　force　as　the　objective.　First　order　optimization　method　is　used　to　determine　the　optimum　design　of　this　problem.　The　optimization　process　works　entirely　with　the　ANSYS　Parametric　Design　Language　(APDL).　The　ANSYS　optimization　module　offers　several　tools　that　attempt　to　address　the　mathematical　model　in　different　ways.　The　design　tools　are　used　to　understand　design　space　and　the　behavior　of　the　dependent　variables.　It　is　showed　that　designing　a　structure　with　ANSYS　optimization　module　and　its　design　tools　is　an　effective　means　to　make　improvements　of　structure.