Influence　of　methane　concentration　on　laminar　burning　velocity　of　coal-bed　gas　under　normal　temperature　and　pressure　is　studied　in　constant　volume　combustion　bomb　with　the　help　of　high-speed　camera　digital　schileren　photography.　Influence　of　methane　variation　on　laminar　propagation　speed　and　laminar　burning　velocity　of　coal-bed　gas　under　different　equivalence　ratios　is　obtained.　The　experimental　results　show　that　with　the　decrease　of　methane　concentration,　both　stretched　laminar　propagation　speed　and　unstretched　laminar　propagation　speed　of　combustible　mixture　decrease　under　different　equivalence　ratios.　The　unstretched　laminar　propagation　speed　that　corresponds　to　different　methane　concentrations　varies　greatly　under　stoichiometric　conditions.　The　principle　of　methane　variation　to　unstretched　laminar　burning　velocity　and　propagation　speed　vary　similarly　with　methane　concentration.