The invention discloses a method and device for achieving low-temperature quick separating of metallic copper in copper slag through the supergravity and belongs to the field of comprehensive utilization of resources. Firstly, 3-5% of carbon powder is added in the copper smelting slag discharging process to serve as a reducing agent to reduce magnetite particles in the slag into ferrous oxide, andthe ferrous oxide and silicon dioxide in the slag form a fayalite phase; then, copper slag melts are continuously added into a supergravity reactor through a flow guiding system, and the temperatureof the copper slag is controlled; and then, a centrifugal rotation system is started, the supergravity reactor is driven by a motor to conduct centrifugal rotation, the gravity coefficient and the separating time are controlled, and continuous separating between the metallic copper and the molten slag is achieved through the supergravity generated by centrifugal rotation. According to the method and device, under the condition of the supergravity, low-temperature quick separating between the metallic copper in the copper slag and the molten slag is achieved, the copper-slag separating efficiency is improved, the purity degree and recovery rate of the metallic copper are increased, the metallic copper with the Cu content being larger than 85% and an iron-slag-rich phase with the Cu contentbeing lower than 0.15% are obtained, and the recovery rate of Cu reaches 97% or above; and according to the method, operation is easy, the cost is low, and continuous production can be achieved.