A　new　formula　for　the　interaction　force　between　two　magnetic　dipoles　in　a　uniform　magnetic　field　is　derived　taking　their　mutual　magnetic　interaction　into　consideration　and　used　to　simulate　their　relative　motion.　Results　show　that　when　the　angle　β　between　the　direction　of　external　magnetic　field　and　the　centerline　of　two　magnetic　dipoles　is　0°or　90°,　magnetic　dipoles　approach　each　other　or　move　away　from　each　other　in　a　straight　line,　respectively.　And　the　time　required　for　them　to　contact　each　other　from　the　initial　position　is　related　to　the　specific　susceptibility　and　the　diameter　of　magnetic　particles,　medium　viscosity　and　magnetic　field　strength.　When　β　is　between　0°and　90°,　magnetic　dipole　pair　performs　approximate　elliptical　motion,　and　the　motion　trajectory　is　affected　by　the　specific　susceptibility,　diameter　and　medium　viscosity　but　not　magnetic　field　strength.　However,　time　required　for　magnetic　dipoles　to　complete　the　same　motion　trajectory　is　shorter　when　adopting　stronger　magnetic　field.　Moreover,　the　subsequent　motion　trajectory　of　magnetic　dipoles　is　ascertained　once　the　initial　position　is　set　in　a　predetermined　motion　trajectory.　Additionally,　magnetic　potential　energy　of　magnetic　dipole　pairs　is　transformed　into　kinetic　energy　and　friction　energy　during　the　motion.　©　2016　Author(s).