Abstract: In order to study the stability of stope and the subsidence of ground surface during the course of mining in southern district of Sijiaying iron mine,one section of mining panel was selected to do the physical and mechanics model test.The distributed optical fiber based on BOTDR was used to monitor the strain of model.It was indicated that the BOTDR-based distributed detection technique for the model was quite effective.Test results show that the model is stable,the movement of stop roof and ground surface is less,the change of strain in the pillar is stable,Bench open stoping and subsequent filling mining is feasible.There were obvious advantages for BOTDR such as distributing,high precision，easy layout，strong anti-interference,and it was a very potential technique for simulation experiment.

Key words: Distributed optical fiber, BOTDR, Bench open stoping, Subsequent filling, Model experiment