The invention relates to the technical field of logistics sorting, in particular to a sorting system and a control method thereof. The sorting system comprises a sorting transportation device, a cabin device, an identifying device and a control device; the bin device includes an upper-layer cabin and a lower-layer cabin; the sorting transportation device includes an upper-layer transportation unit, a lower-layer transportation unit and a driving unit; the driving unit is used for driving the lower-layer transportation unit to horizontally rotate, and the rotating point of the lower-layer transportation unit is eccentrically arranged; a discharge port of the upper-layer transportation unit is formed in a corresponding position above the rotating point of the lower-layer transportation unit; the lower-layer transportation unit is a two-way transportation structure with two discharge ports; the two discharge ports are respectively corresponding to the upper-layer cabin and the lower-layer cabin, and are in signal connection with the control device; and the control device is electrically connected with the upper-layer transportation unit, the lower-layer transportation unit and the driving unit. The sorting system solves the technical problem of difficult sorting of objects to be sorted into a double-layer annular cabin by the sorting transportation device.