By using the equilibrium moisture content-time lag methods of Nelson and Simard and the meteorological element regression method, this paper studied the dynamics of the moisture content of ground surface fine dead fuels under a Larix gmelinii stand on the sunny slope in Daxing' anling with a time interval of one hour, established the corresponding prediction models, and analyzed the prediction errors under different understory densities. The results showed that the prediction methods of the fuels moisture content based on one-hour time step were applicable for the typical Larix gmelinii stand in Daxing' anling. The mean absolute error and the mean relative error of Simard method was 1.1% and 8.5%, respectively, being lower than those of Nelson method and meteorological element regression method, and close to those of similar studies. On the same slopes and slope positions, the fuel moisture content varied with different understory densities, and thus, it would be necessary to select the appropriate equilibrium moisture content model for specific regional stand and position, or establish the fuel moisture content model based on specific stand when the dynamics of fuel moisture content would be investigated with a time interval of one hour.