The invention discloses a method for discharging paste tailings to the movably-settling open pit bottom. The method comprises the following steps: S1, evaluation of tailings sand; S2, detection of a paste tailings sample; S3, arrangement of the movably-settling open pit bottom; S4, discharging of the paste tailings. According to the method for discharging the paste tailings to the movably-settling open pit bottom, an open pit is adopted as a tailings stacking pond for underground mining, a series of problems about construction of the mine tailings pond is effectively solved, and construction and maintenance funds of the tailings pond are saved on the premise that the underground mining operation safety is guaranteed. Besides, the disaster of instability of the open pit slope can be effectively controlled, the underdrainage cost is saved, the problem that tailings sand cannot be discharged on a coverage layer with a caving mining method is solved, reclamation of the open pit is facilitated, the mining cost is greatly saved, and the environment is protected.