Abstract: It is very important to ensure the safe production of the mine by keeping the stability of the goaf at one-step ore chamber with the stage open stope and subsequent filling method. The exact shape of goaf can be obtained by accurately detecting of goaf. The Surpac model of goaf is imported into FLAC3D software， which is different from the simple regular shape of ore body model. This method can greatly realize the accuracy of stability analysis and the visualization of digital mine. Taking a Daye Iron Mine as a case， the goaf detection model of one-step chamber stoping with subsequent filling method was measured by VS150 instrument. The goaf detection model can be truly displayed in FLAC3D software through corresponding coupling program. Also， the ore recovery rate and the ore dilution rate can be accurately obtained by combining the designed orebody model with the measured goaf model. The index shows that the overdraft of orebody is 1 423.4 m3，the undermining is 1 413.3 m3. A high-level recovery rate and an expected result have been achieved. At the same time， combining with mechanics parameters of the actual engineering rock mass， the stability of the goaf after excavation of ore chamber was calculated. According to the field engineering practice， it is proved that this method is correct， and the Surpac-FLAC3D coupled stability system for the goaf is of great value in application.

Key words: Mined-out area scanning, Geological model, Surpac-FLAC3D coupling, Stability