Overcapacity in China’s coal industry has serious negative impacts on the rational allocation of coal resources and stable operation of the national economy. Since 2016, the Chinese government has implemented a series of de-capacity policies to optimise coal production capacity. Timely policy effect assessment is of great significance to the government to guide high-quality development of the coal industry. This paper first reviews the dilemma encountered by China’s coal industry prior to 2016, and then analyses the progress and effect of coal industry de-capacity. The main results are as follows: (1) The capacity reduction is mainly distributed in the central and southwestern regions. Most of the coal mines are state-owned, and there is a prominent worker resettlement problem. (2) The capacity optimisation policy has accelerated the implementation of the overall spatial planning of China’s coal supply. China’s coal production centre has shifted from the central and eastern regions to the west, and the industry’s high-quality development pattern has taken shape. (3) China’s coal industrial profitability has constantly been improving, industry concentration has increased significantly, and coal mining has become safer. (4) Due to the regional heterogeneity, the de-capacity policy effect has significant differences in coal production capacity and employee reduction in various regions. Finally, regarding the optimisation of China’s coal production capacity, some policy implications are given.