Abstract: Forest fire is one of the major disasters endangering forest health, thus the accurate prediction of forest fire danger has great significance for fire prevention. Aiming at the problem of lacking small-scale forecast for forest fire danger grade in China, the paper proposes a new fire weather forecasting method based on the MTCLIM model and the WindNinja software, studies the calculation and generation techniques of forest fire danger factors in sub-compartment, and realizes the fast fire weather forecast for forest sub-compartment. The results showed that this method was easy to implement, of good universality, and can calculate quickly the temporal and spatial variation of the fire danger levels of forest sub compartments. Thus it has good guidance and reference significance to improve the work of fire fighting and prevention.