In the gangue filling face of Xingdong Mine, a large special gangue filling support was used in conjunction with the hanging rear scraper conveyor to carry out gangue filling mining. When the gangue filling mining operation was carried out in the face with a large inclination angle, the working face often ran up and down, which seriously restricted the advancement of the working face. Taking No.1222 Face as an example, the mechanical analysis of the overall sliding and falling of the gangue filling support was made. The comprehensive effects of various technologies, such as advancing the roadway, adjusting the end support, connecting three boats at the top and bottom, and installing an anti-falling system on the basic support, were adopted to prevent the gangue filling support from falling and sliding. The field practice showed that the anti-toppling and anti-sliding of gangue filling support had achieved good results in the process of advancing in No.1222 working face, which had good economic and social benefits.