A data processing method includes: determining, by a PDCP entity of a terminal, at least one first transmission path corresponding to PDCP duplication that needs to be changed from an activated state to a deactivated state, from a transmission path set corresponding to PDCP duplication and including at least one transmission path currently in an activated state; and indicating, by the PDCP entity of the terminal, to a RLC entity corresponding to the first transmission path to discard duplicated data, in a case where the at least one first transmission path is not all transmission paths in the transmission path set. The transmission path set comprises at least one transmission path and a main transmission path.