Magnetorheological　fluid　(MRF)　damper　is　one　of　the　most　promising　semiactive　devices　for　vibration　control.　In　this　paper,　a　shear-valve　mode　MRF　damper　for　pipeline　vibration　control　is　proposed.　The　dynamic　model　and　the　state　equation　of　the　pipeline　are　established　and　the　linear　quadratic　regulator　(LQR)　is　used　to　generate　the　optimal　damping　force　of　MRF　damper.　The　design　concept　considering　the　structure　and　the　electromagnetic　properties　simultaneously　is　discussed　in　detail.　A　mathematical　model　of　the　relation　between　shear　stress　and　control　current　based　on　interpolation　method　is　established.　Finite　element　analysis　(FEA)　software　COMSOL　is　selected　to　simulate　the　magnetic　field　and　electromagnetism-thermal　field　of　the　MRF　damper.　A　computational　method　based　on　the　simulation　model　is　established　to　calculate　the　shear　stress.　In　order　to　reduce　the　magnetic　leakage,　a　method　of　adding　magnetism-insulators　at　both　ends　of　the　piston　head　is　presented.　The　influence　of　control　current,　displacement,　and　velocity　on　mechanical　performance　of　the　proposed　MRF　damper　is　experimentally　investigated.　The　test　results　show　that　the　performance　of　the　MRF　damper　is　basically　identical　with　the　theoretical　prospective　and　the　simulation　conclusions,　which　proves　the　correctness　and　feasibility　of　this　design　concept.