Abstract：Cooling system is widely used in deep coal mines of China for the increasing heat and humid hazard, which are the problems caused by the deep mining. Air cooler, locating at the mining tunnel, is easily fouled by the hot, humid and dust air. The Euler-Lagranian model was taken in this article to study the mechanism of fouling on the gas side of air cooler under hot and humid deep coal mine. And the results indicated that when the dust particle size is less than 10 μm, the dust particles are less affected by gravity, and the fouling distribution on the pipe wall is more uniform. When the dust particle size is larger than 10 μm, the dust particles are more affected by gravity, and the fouling distribution is mainly concentrated in the front tube. Dust deposition is negatively correlated with air velocity, water temperature in pipe and positively correlated with relative humidity. Studying the fouling mechanism of air cooler in hot and humid dusty environment of deep wells has theoretical guiding significance for the research of efficiently preventing and suppressing scaling and scale removal technology, the performance of air cooler.