From September 1937 to August 1945, during the Japanese occupation of the coal mines in Datong, the invaders ruthlessly plundered coal resources and forced workers to labor under brutal conditions and harsh living environments. Under their control, the coal production in Datong increased from 870,000 tons in 1938 to 2.27 million tons in 1942, according to the museum.

Many miners, who were either killed or left on the brink of death, were discarded in desolate areas, riverbanks, valleys and abandoned mine shafts, creating over 20 mass graves filled with bones.

For the museum's director Guo Dianjun, the mass graves site stands as a witness to Japan's policy of "exchanging blood for coal". Officially opened in 1969, the museum spans 68,000 square meters, with a black granite memorial wall inscribed with the numbers 14,000,000 (tons of coal looted) and 60,000 (lives lost).

Its five exhibition sections trace Japan's invasion, coal plunder, laborer enslavement, and postwar remembrance with immersive displays including reconstructed mass graves, survivor testimonies via holograms, interactive media, and excavated artifacts. There are more than 300 file photos and about 80 relics.

Due to limited domestic supplies of natural resources, such as coal, iron ore and oil, Japan looked to Datong to secure access to coal after its rapid industrialization during the late 19th and early 20th centuries.

According to Wang, during Japan's occupation of the city, Japanese invaders forcibly conscripted laborers from famine-stricken regions like Henan and Hebei provinces under false promises of job opportunities.