Accurately grasping the dynamic development law of deformation and failure of the mining floor above the confined aquifer constitutes the fundamental basis for ensuring safe and efficient mine production. Through a combination of theoretical analysis and in-situ measurement, an in-depth exploration and analysis was conducted on the deformation and failure mechanism of the bottom floor during the upper layer coal seam mining. The outcomes of traditional mechanical calculations indicated that after the mining of the upper layer of the 3# coal seam, brittle fractures occur within the range of 0 ~ 7.4 m, while plastic fractures taken place between 7.4 m and 12.6 m. According to the mining progress of the working face, the response characteristics of rock strata at different stages can be dynamically obtained, facilitating a comprehensive analysis of the deformation and failure laws of the floor strata. The in-situ test results reveal that during the strata mining of the 3# coal seam, the influence distance of the leading abutment pressure of the working face reaches 25.9 m, the deformation and failure depth of the floor is measured at 12.5 m, and the resistivity value of the rock layer in the damaged area is approximately 8 ~ 10 times that of the background value. Meanwhile, the distributed optical fiber test results demonstrate a high degree of consistency with the resistivity test results, with an absolute error of merely 0.02 m and a relative error of 0.16%. The practical application results show that the test results of borehole parallel electrical method are clear, which can accurately depict the deformation and failure shape of the rock strata and effectively improve the interpretation ability of the internal deformation and failure of the rock strata.