In order to reveal the evolution patterns of weathering and disintegration characteristics of coal gangue under the climatic conditions of Northwest China, fresh coal gangue from the Shendong Mining area was selected as the research subject. Laboratory simulation experiments were performed. Changes in macroscopic indicators, including D₅₀, disintegration rate, and sphericity of coal gangue across various particle sizes, were analyzed. The deterioration patterns of slake-durability under different weathering cycles were systematically investigated. Differences in slake-durability among coal gangue of different particle sizes were examined.The results indicate that the disintegration of coal gangue follows a spherical disintegration process. As the particle size increases, the sphericity and slake-durability of coal gangue show a consistent trend of first decreasing and then significantly increasing. The disintegration process demonstrates a “slow-fast-stable” deterioration pattern. After 30 weathering cycles, the sphericity of coal gangue across all particle sizes stabilizes at approximately 86.1%. At this point, the disintegration reaches a steady state. S_p=86.1% is identified as the critical threshold for the slake-durability of coal gangue material. Coal gangue with S_p≥86.1% is considered to be in a stable structural state.Regarding slake-durability, the following order is observed: coarse gravel gangue (from 46 mm to 80 mm) > fine gravel gangue (from 5 mm to 20 mm) > medium gravel gangue (from 21 mm to 45 mm). Medium gravel gangue (S_p=81.5%) exhibits lower sphericity and possesses numerous angular structures, making it more prone to disintegration.