To　get　the　effect　of　hydrogen　addition　under　different　initial　pressures,　different　initial　temperatures　and　different　initial　equivalence　ratios　on　combustion　pressure,　relevant　tests　of　methane-hydrogen-air　mixture　have　been　carried　out　in　constant　volume　combustion　bomb.　The　results　showed　that　higher　initial　temperature　and　lower　initial　pressure　is　helpful　to　get　higher　flame　propagation　velocity　while　other　initial　conditions　keep　invariable;　as　hydrogen　blend　ratio　increases,　both　maximum　combustion　pressure　and　maximum　rate　of　pressure　rise　increase,　with　the　appearance　time　obviously　earlier　and　cycle-to-cycle　variation　obviously　lower.