The　combustion　characteristics　of　methane-hydrogen-air　mixture　in　constant　volume　combustion　chamber　are　studied　in　the　case　of　different　initial　temperatures,　initial　pressure,　equivalent　ratio　and　hydrogen　blend　ratios.　The　effects　of　the　above　conditions　on　maximum　combustion　pressure,　rate　of　maximum　pressure　rise,　flame　development　time,　combustion　duration,　and　cyclic　variation　of　maximum　combustion　pressure　are　obtained.　The　results　show　that　the　higher　temperature　and　the　lower　pressure　are　helpful　to　achieve　the　higher　flame　propagation　velocity　while　other　initial　conditions　keep　stable;　as　the　hydrogen　fraction　increases,　both　the　combustion　velocity　and　combustion　peak　pressure　gradually　rise,　the　appearance　time　of　combustion　peak　pressure　is　moved　up,　and　the　variation　coefficient　is　obviously　lower.