Abstract: Aiming at the problems of poor stope operation safety conditions and large ore loss and dilution when the steeply inclined medium-thick broken orebody is mined by the shallow hole retention method.Taking Xilinhot Fluorite Mine as the engineering background,a systematic study on the safe mining technology of open stoping with subsequent filling in steeply inclined medium-thick broken orebody is carried out from the aspects of the rock mass cavability,technological improvement,caving prevention and control.Based on the analysis of rock caving capability,a rock mass caving mechanics model is constructed.The calculated limit caving span is 5.4~6.4 m,which is less than the average thickness (7 m) of the orebody,it is a risk of caving accidents.From the point of view of operation safety and loss and dilution control,the empty field subsequent filling and mining technology based on the vertical deep hole caving stage ore house method is proposed,and the stope structure layout method is given.Using sub-level collapse,middle section and stage ore drawing method,the reasonable caving step is determined to be 1.56 m.On this basis,the impact of the roof caving in the mined-out area is analyzed.The calculated impact air wave value formed by the roof rock mass falling in the goaf is 34.96 m/s,which far exceeds the value specified in the Safety Regulations for Metal and Non-Metallic Mines (GB 16423—2020).A safe loose cushion laying method to prevent falling impact disasters is given,and the reasonable thickness of the bulk cushion layer is 3.3 m.Through on-site industrial tests,stope operations are safe,the ore recovery rate is increased by 7.31%,and the dilution rate is reduced by 7.66%.The economic benefits are significant,and safe and efficient mining of this type of mine can be realized.