Abstract: In Sunjiagou Coal Mine,the deformation and failure of the coal seam floor occurre during the mining process of deep thick coal seams,which pose a serious challenge to safety production.In order to analyze the deformation and failure situation of the coal seam floor rocks,uniaxial loading strain tests are carried out on standard rock samples based on Brillouin Optical Frequency Domain Analysis （BOFDA）,and electrodes and distributed optical fibers are placed in the coal seam floor monitoring boreholes to monitor the deformation of the coal seam floor in real time.The results indicate that the deformation of rock samples can be divided into five stages:initial compression,linear elastic deformation,micro rupture derivation,plastic deformation,and final failure;The electrode current value,optical fiber strain value,and floor deformation have a good response relationship.When the floor rock is not broken,the electrode current value is positively correlated with the distributed optical fiber strain value.When the floor rock mass continues to break,the electrode current value and optical fiber strain value undergo a sudden change;The failure depth of coal seam floor is developed to 21.0 m,located at the lower part of the mudstone-limestone boundary.The research results can provide theoretical basis and technical support for coal mine safety production.