The invention discloses a photometric sorting process for coal gangues arranged in a coal mine underground roadway. According to the photometric sorting process for the coal gangues arranged in the coal mine underground roadway provided by the invention, on the basis of the development of an existing technology, by breaking through a traditional ground stacking type arrangement idea and optimizingspace-time connection of various working units in a process flow, a coal mine underground modular compact type high-efficiency sorting system is built, process steps such as coal mining, raw coal preparation, coal gangue photometric sorting, and gangue backfilling are accurately matched and cooperatively optimized, so that the coal mine underground modular compact type high-efficiency sorting system is suitable for a coal mine with the content of +150mm particle size in raw coal being below 10 percent and a brittle coal property, the coal mine underground gangues can be discharged from the source, the number of the gangues lifted to the ground is reduced, the transporting and filling cost is saved, and an environmental requirement is met. Meanwhile, according to high-efficiency sorting ofthe coal mine underground gangues provided by the invention, the gangue lifting amount can be reduced, the mining quantity and the production efficiency of a coal mine are effectively improved, and atechnical support is provided for coal mine underground mining-washing-filling cooperation work; and meanwhile, the sorting process provided by the invention has no special requirements on the coal mine underground roadway and a chamber, and is suitable for an underground narrow chamber space.