The invention discloses a ballast separation system. The ballast separation system comprises an explosive bolt and a plurality of relays in serial connection with the explosive bolt, wherein the plurality of relays comprise a plurality of redundant relays. According to the ballast separation system, the relays are controlled to power up the explosive bolt so as to realize ballast separation and reduce the ballast dry weight, so that the purpose of maintaining the buoyant weight balance of a balloon is achieved, and the hang time of the balloon in a near space is prolonged. Meanwhile, a control circuit is simplified and large-scale production is facilitated.