Abstract: As the last line of defense to ensure the safety of personnel and equipment, the core of open-pit mine slope monitoring lies in establishing accurate early warning thresholds. Currently, in China's open-pit mine slope monitoring systems, there are issues of lacking a systematic approach to setting early warning thresholds and lacking scientific theoretical support for threshold determination. To address this, this study proposes an early warning method based on creep theory: by focusing on the development patterns of creep curves and the variation characteristics of cumulative displacement, the early warning thresholds are determined through analyzing the proportional relationships of critical displacements in the three stages of slope creep. First, obtain the stress-strain curve through simulation, calculate the elastic modulus and viscosity coefficient required for creep analysis, and then establish a creep equation to derive the displacement proportional relationship. Based on the simulated creep curve, the key points required for the equation and the starting values of tertiary creep are obtained. By combining the theory of locked segments and renormalization group, the critical displacement threshold is determined, thereby deriving the four-level early warning thresholds for creep evolution. These thresholds are then compared with GNSS monitoring data to verify their accuracy. For sudden abnormal deformation, the tangent angle criterion is introduced to improve the early warning mechanism. Tests show that, taking the early warning threshold of open-pit mine C as an example, the monitoring system issued a Level I warning (6216 mm) 11.6 days in advance of landslide occurrence . Subsequently, short-term monitoring of the deformation rate early warning threshold was carried out: after the system issued a Level I warning based on the deformation rate (97.2 mm?d?1), the landslide occurred 3 hours later. Through the synergy of long and short-term early warnings, the accuracy and reliability of the early warning system have been improved.