The invention discloses a nuclear waste packaging body dual-mode synchronous scanning detecting device which comprises a rotation platform, wherein the rotation platform is connected with a rotation driving mechanism; a first ascending and descending platform, a second ascending and descending platform and a third ascending and descending platform are arranged around the rotation platform; a transverse moving platform is arranged on the first ascending and descending platform; the transverse moving platform is connected with a transverse moving driving mechanism; a single HPGe detector systemis arranged on the transverse moving platform; a transmission source and a collimator assembly are arranged on the second ascending and descending platform; a matrix detector system is arranged on thethird ascending and descending platform; and a matrix detector of the matrix detector system, the transmission source, the collimator assembly and a single HPGe detector of the single HPGe detector system respectively face the rotation platform. Compared with the existing single HPGe detector, the nuclear waste packaging body dual-mode synchronous scanning detecting device has the advantage thatthe work efficiency is obviously improved. Compared with the existing array type HPGe detector, the nuclear waste packaging body dual-mode synchronous scanning detecting device has the advantages thatthe manufacturing cost is low; both economical performance and universality are considered; the scanning efficiency of TGS (Tomographic Gamma Scanning) can be obviously improved; the measuring time is shortened; and the TGS speed is accelerated.