The invention relates to a raw material charging system used for a continuous gas retort. The system is arranged between an upper charging opening and a raw material bin of the gas retort. The charging system comprises a dual sealing and feeding device and a buffering stock bin. A feed inlet of the dual sealing and feeding device and a discharge opening of the raw material bin are connected, a discharging port is connected with a feed inlet of the buffering stock bin below, and a discharging port of the buffering stock bin extends in a retort retorting chamber. The feed inlet and the discharging port of the dual sealing and feeding device are each provided with a seal gate, and a material level meter is further arranged on the top of the dual sealing and feeding device. The quantity of materials added into the retorting chamber can be accurately controlled. Besides, gas in the retorting chamber and gas outside the retorting chamber can be isolated, and air leakage is prevented; meanwhile, the quantity of the materials in the retort can be detected, frequent routing inspection by workers is not needed, and labor intensity is reduced.