Since Chinese historic buildings have a unique wood structure, the fire load is used as the key parameter to determine the fire risk. In this study, the aim is to examine the fire risk of historic wooden buildings in Beijing by identifying the fixed fire load (FFL) and movable fire load (MFL) for a sample of 83 historical buildings. It is found that the fire load is averagely 2847.7 MJ/m and dominated by the fixed one, which is significantly different from that of conventional modern buildings. The fire load is proven to have an extreme value III distribution. The roof board, pillars, and beams contribute the most to the FFL and the FFL from the roof board has almost a constant value of 482.6 MJ/m. By a K-Means clustering algorithm, it is found that the FFL first decreases and then increases with a greater floor area, which could be explained by the evolutionary process of a historic building’s size. The sample historic buildings are classified by five types of usages to determine the MFL. Finally, an estimation matrix of the fire load of historic buildings is proposed based on the above statistical results.