In　this　paper,　a　method　to　measure　the　flow　speed　based　on　microfluidic　chip　by　digital　holography　in　real-time　is　demonstrated　experimentally.　The　injection　pressure　of　microfluidic　device　is　changed　to　create　different　flow　rate　in　microfluidic　channels.　On　this　basis,　the　phase　distributions　within　the　microfluidic　channels　can　be　reconstructed　by　using　digital　holographic　microscopy,　and　then　flow　rate　can　be　obtain　by　measuring　the　phase　distributions　of　cross　section.　The　experiment　results　show　that　digital　holographic　phase　image　is　an　effective　and　real-time　detection　means　for　the　characteristic　parameters　of　micro-fluid　such　as　flow　rate　and　injection　pressure.　In　addition,　the　chip　calibration　is　made　to　ensure　the　validity　of　the　experimental　results.