The invention provides a backfilling method and device of a shore-connecting zone. The method comprises the following steps: forming packing by an earth material and a curing agent and injecting the packing into a conveying pipeline; and conveying the packing to the shore-connecting zone through the conveying pipeline for backfilling the shore-connecting zone. The invention further provides the device for backfilling the shore-connecting zone. According to the method and device, the self-weight of backfilled materials is reduced, soil pressure generated by the pile-up effect is reduced and the risk that a subjacent foundation has landslide due to instability is reduced; and moreover, the scale of the foundation and the treatment scale of the subjacent foundation are reduced, and the cost is reduced.