Abstract: The soft-rock slope of the surface coal mine has complex deformation and great landslide risk. In order to fully excavate the change law of the monitoring data of the soft-rock slope of the surface coal mine and realize the accurate prediction of the landslide of the soft-rock slope, the No.2 surface mining area of the Huolinhe Coalfield was taken as the engineering example, based on the theoretical calculation of tangent Angle of creep curve, the classification standard of radar warning threshold levels for different types of soil-rock complex soft-rock slope were innovatively proposed. The results show that the deformation speed of the early warning threshold of the middle-upper part of the stope soil slope and the dump slope is v≥15.0 mm/h, and the tangent Angle α≥75° reaches the imminent slip stage, the early warning threshold velocity v≥8.0 mm/h for hard rock slopes in the lower stopes, and the tangent Angle α≥85° reaches the imminent slip stage. The successful application of the warning threshold is of great significance to ensure the safety of mine production and improve economic benefits.