Packet data convergence protocol PDCP entity and execution method thereof

The invention discloses an execution method of a packet data convergence protocol PDCP entity and corresponding entity equipment. The method comprises the steps of: mapping packet data convergence protocol protocol data units PDCP PDU, which are received from a lower entity of the PDCP entity and arrive disorderly, to PDCP SDUs, and storing the PDCP SDUs in a re-ordering buffer area; judging whether serial numbers of omitted PDCP SDUs are smaller than a relatively small one of maximum serial numbers of the PDCP SDUs respectively received from two lower entities by the PDCD entity; and if the serial numbers of the omitted PDCP SDUs are smaller than the relatively small one, submitting the PDCP SDUs stored in the re-ordering buffer area whose serial numbers are smaller than the serial numbers of the omitted PDCP SDUs, and the PDCP SDUs whose serial numbers are larger than and continuous with the serial numbers of the omitted PDCP SDUs to an upper entity of the PDCP entity.