Study results are presented concerning the relationship between the velocity of methane-hydrogen flame propagation in the first and second phases of combustion with the concentration of hydrogen in fuel and the intensity of turbulence. The first phase of combustion corresponded to the spread of the flame at the ignition spark plug, and the second phase- combustion of the bulk of fuel due to the development of the turbulent flame front to a larger volume of the combustion chamber. It is shown that the effect of turbulence intensity on the flame propagation velocity depends on the combustion phase. The larger the size of the combustion chamber, the stronger effect of turbulence and the coefficient of excess air — when burning stoichiometric mixtures, the increase in turbulence leads to a more noticeable increase in the flame velocity than when burning poor and rich mixtures. It is found that the higher the concentration of hydrogen in the combustible mixture, the greater the rate of flame propagation in both combustion phases. In this case, the promoting effect of hydrogen on the flame velocity is more manifested in the first combustion phase. Processing of studies results of the foreign and domestic scientists showed reasonableness of the revealed regularities for combustion chambers of different designs. The results of the work can be used in the design and further development of energy-efficient and low-emission combustion chambers, as well as in the development of industrial and fire safety rules for power plants where the hythane is used.