Coal gangue has been the biggest industrial solid waste discharged in our country, with the cumulative stockpile of more than 7 billion tons. The accumulation and discharge of coal gangue occupy a large amount of land, pollute the soil, air and water, and has caused a great ecological environment impact. Currently, the comprehensive utilization of coal gangue in our country has the characteristics of low utilization rate, single product, poor performance, and difficult compatibility between large-scale and high added value. The scale and ability of existing coal gangue harmless and comprehensive utilization of resource can not meet the country's practical requirement for the ecological environment protection and "double carbon" target on carbon emission reduction. In order to promote the development of comprehensive utilization technology of coal gangue, in this paper, the composition and physical and chemical characteristics of coal gangue were described, and the application status of coal gangue resource in the field of building materials was discussed including coal gangue making cement, concrete aggregate and wall materials. Secondly, the influence of coal gangue on ecological environment was analyzed from the aspects of heavy metal leaching, dust and gas pollution. Finally, on this basis, the innovative strategies of collaborative complementation and two-stage iterative utilization of coal gangue as well as some suggestions and prospects were put forward.