According to control theories, mine fires can be considered as an unsteady process after the normal ventilation system is disturbed. Applied the principal of physical chemistry and thermal fluid mechanics, the parameters models of the unsteady state system have been given, such as fuel combustion rate, heat of combustion, concentration, temperature, heat losses, heat resistance, work of expansion and heat pressure difference. The results of the calculation agree approximately with the results of the test. By the computer simulation, it is shown that the main factor of producing the throttling effect is the fire rate, second is the heat resistance and the heat pressure difference. The rate of heat flow that passes through the airway wall is the maximum on the surface, and decrease with time. The heat transfer progresses only within the range of 0.5 m away from theairway wall during combustion for 2 hours. It’s variable for the mass flux rate and the percentage concentration of the gas along the airway of the downstream. When the delayed time is very small, the variation can be neglected. Viscosity resistance is the main part of the heat resistance, second is the expansion resistance that is less than tens Pascal when Mach number is very small. Work of expansion is principally turned into heat losses, only a very small part is consumed by the work of the heat resistance and the inertia acceleration. Applied the principal of physical chemistry and thermal fluid mechanics, the parameters models of the unsteady state system have been given, such as fuel combustion rate , the heat of combustion, concentration, temperature, heat losses, heat resistance, work of expansion and heat pressure difference. The results of the calculation agreement approximately with the results of the test. By the computer simulation, it is shown that the main factor of producing the throttling effect is the fire rate, second is the heat resistance and the heat pressure difference. The rate of heat flow that passes through the airway wall is the maximum on the surface, and decrease with time. The heat transfer progresses only within the the range of 0.5 m away from the airway wall during combustion for 2 hours. It’s variable for the mass flux rate and the percentage concentration of the gas a long the airway of the downstream. When the delayed time is very small, the variation can be neglected. Work of expansion is principally turned into heat losses, only a very small part is consumed by the work of the heat resistance and the inertia acceleration.