Abstract: When using the sublevel open stope subsequent filling method in mines, the height of the sublevel increases, and the exposed area of the empty area increases after a single blasting, which can easily lead to safety issues such as surrounding rock caving in the mining area. Takes the study of mining methods for a fractured gold orebody with altered faults as an example, the RMR method and Q system are used for rock mass classification on the basis of drilling core investigation, point loading, and laboratory testing. Uses the quantitative equiprobability line-Mathews synthesis diagram to analyze stability probability is compared in the variation range of stope width of 8-15 m and stope length of 20-50 m at 60 m level height. The results show that the east and west regions of the orebody are partially broken due to the fault and parallel alteration zone. With the increase of the buried depth of the orebody, and the integrity of the orebody and surrounding rock in the west region improves by the parallel veins of the upper surrounding rock pinches out. The recommended stope width for the ore body in the eastern district （thickness 30 m） is 11 m, and for the ore body in the western district （thickness 25 m）, the stope width should be controlled within 10.5 m. On these conditions, the stability probability of each exposed surface of the stope could be greater than 80%. The application of this method has played a key technical role in safe mining and can provide important technical support for the mines using similar mining methods.