Abstract: In this paper, the laminar combustion velocity of low calorific value gases blended hydrogen is experimentally studied in the constant volume combustion bomb.An experimental system of constant volume combustion bomb was set up, and the variation trend of laminar flame velocity of low calorific value blended hydrogen is analyzed under different initial conditions.The experimental results show that increasing the initial pressure will reduce the laminar combustion speed of the flame, while increasing the initial temperature will increase the laminar combustion speed of the flame.With the increase of hydrogen ratio, the laminar combustion speed of flame and instability of flame increases.The influence of equivalence ratio on laminar combustion velocity of flame is quite complex, generally, the burning speed of the rich mixture is greater than that of the lean mixture.The research in this paper can provide experimental basis for the design and development of low calorific value blended hydrogen engine.