According　to　the　mathematical　model　of　a　brushless　DC　motor,　using　MATLAB　/　Simulink　to　build　various　independent　functional　modules,　and　integrated　into　the　simulation　model　of　brush　less　DC　motor　control　system.　The　system　uses　the　double　loop　of　control　mode,　including　the　inner　current　loop　and　the　outer　speed　loop,　to　ensure　that　the　motor　is　performance　well　in　the　high　and　low　speed,　and　system　has　start　fast,　flexible　control,　robustness　and　other　advantages.　By　conducting　the　two　simulation　experiments　of　tracking　the　speed　and　keeping　the　speed　stability,　we　preliminarily　verify　the　effectiveness　and　reasonable　of　the　system　modeling　method　and　the　feasibility　of　the　control　system　design,　simulation　and　setting　parameters　can　also　be　made　to　optimize　the　actual　controller　control　and　commissioning　reference.