The invention belongs to the field of devices for blood component separation, and relates to a double-layer-flow path integration device for a centrifugal bag type blood component separator. The integration device comprises an upper cover plate, a middle integration body and a lower cover plate from top to bottom, the middle integration body comprises an outer shell, the interior of the outer shell is partitioned into an upper layer and a lower layer by a middle partition plate, anticoagulant pipes, a brine pipe, a blood collection pipe, a blood return pipe, centrifugal pipes, plasma pipes, erythrocyte pipes, PRP pipes, blood platelet pipes, a whole blood pipe and mixing pipes are distributed on the upper layer and the lower layer, a plurality of connectors distributed in a two-layer mode are arranged on the periphery of the outer shell, and the connectors communicate with corresponding pipelines arranged in the upper layer and the lower layer. The integration device has the advantages that the structural design is reasonable, the pipeline structure is simple, in actual use, the number of parts which are required to be matched with the device for use is few, the safety is high, the damage rate is low, and the service life is long; and in the circulation process of blood, air is not prone to mixture, so that the damage probability of a blood donor is reduced.