The invention discloses a full-automatic bag-feeding type packaging machine, comprising a rotating disc (13), a large cam (14), a bag feeding device (1), a marking device (2), a bag opening device (3), a material charging device (5), a heat-sealing device (6), a bag discharging device (7) and a bag bracing device (4). A bag clamping device (39) is arranged at the edges of the rotating disc (13); the bag feeding device (1), the marking device (2), the bag opening device (3), the material charging device (5), the heat-sealing device (6) and the bag discharging device (7) are all arranged outside the rotating disc (13); and the bag bracing device (5) is of a swing arm type and is movably mounted on the rotating disc (13). The packaging machine is characterized in that the bag feeding device (1), the bag opening device (3), the material charging device (5), the heat-sealing device (6) and the bag discharging device (7) are symmetrically arranged around the central point of the rotating disc (13); and the bag bracing device (4) is symmetrically arranged around the central point of the rotating disc (13). The full-automatic bag-feeding type packaging machine with the structure has the advantages of stable performance and high production efficiency.