Abstract: To ensure the safe operation of a certain open-pit coal mine，multiple sources of monitor⁃ ing data were integrated to conduct a time correlation analysis of the GNSS，slope radar，rain gauge，and water measurement weir data from the deformation area of the northern slope of the mining area.This fur⁃ ther analyzed the causes of the deformation in this area and quantitatively studied the slope stability of this area through numerical simulation.The results show that due to rainfall and the infiltration of water from the upper dump area，the groundwater level in the northwest loop area of the northern slope of the mining area has risen，which in turn triggered slope deformation.When the groundwater level in the core of the deformation area decreased from 1 153 m to 1 140 m，the safety factor increased from 1.057 to 1.207，in⁃ dicating that the groundwater level is an important influencing factor for the stability of the slope in this ar ⁃ ea.The numerical simulation results are consistent with the slope monitoring results，verifying the effec⁃ tiveness of the multi-source data fusion analysis in revealing the causes of slope deformation.The study proposed measures for preventing slope deformation，which can provide some references for slope treat ⁃ ment.

Key words: multi-source monitoring, slope deformation, groundwater level, stability analysis