Abstract: The mining method of open-underground combined mining is a necessary requirement to solve the sharp increase of current energy demand. However, the stability of slope under open-underground combined mining is a necessary factor to control resource recovery. Therefore, the study on the stability and timeliness of the slope in Antaibu Mine is carried out to recover the deformation characteristics and deformation modes of the side slope in the open-underground combined mining. The results show that there is no large deformation and failure in the slope under the surface mining and the maximum displacement is 0.75 mm (0.15 m). Under the condition of well mining, there are obvious settlement phenomena on the slope with the advancing of working face, and the maximum settlement value is 8.9 mm (1.78 m). After the surface mining, the slope deformation and failure basically follow the stable creep state with the maximum deformation of 0.97 mm (0.194 m). After the mining reaches the excavation critical line, the change of time, slope settlement value is different, and the maximum settlement value is 0.64 mm (0.128 m).