Abstract: Based on the Bernoulli principle and computational fluid dynamics (FLUENT) software, the meteorological factors influencing ventilation, smoke emission of vernacular dwelling and leading to carbon monoxide poisoning accident were analyzed in the north areas of China, and numerical simulation was employed in order to discuss the early warning method of carbon monoxide poisoning accident in terms of meteorological factors. The results indicate that the main meteorological conditions influencing ventilation and smoke emission of vernacular dwelling in the north areas of China include wind speed, air temperature (difference between the indoor and outdoor air temperature), air pressure and relative humidity. Wind speed is the main factor affecting ventilation, smoke emission and carbon monoxide poisoning accident of vernacular dwelling, furthermore, the change of air pressure and the difference between the indoor and outdoor air temperatures are also important when wind speed is very weak. Based on the above-mentioned, the calculation method on meteorological index of ventilation and smoke emission in vernacular dwelling is established and early warning method of carbon monoxide poisoning accident in terms of meteorological conditions is set up. The effect of early warning method is better after testing.