The invention discloses an error code negotiation method of a
quantum key distribution system, solves the problem that the negotiation efficiency is reduced due to collision in the error code negotiation process of a conventional
Cascade algorithm, and belongs to the technical field of
quantum communication. The method comprises the following steps: S1, in the first round, carrying out
parallel processing on a binary lookup odd-even error correction process; S2, in the second round, obtaining blocks containing odd errors, placing the block with the highest
collision probability in a processingset, and placing the rest blocks in an error set; S3, calculating the
collision probability of blocks in the error set and the
processing set, putting n blocks with the minimum collision probabilityin the error set a into the
processing set, conducting one-step binary search odd-even error correction on the blocks in the
processing set in parallel each time, when the error blocks are found, removing the blocks from the processing set, determining the positions of the error blocks in the previous round, and if the blocks are in the error set, removing the blocks are removed, and otherwise adding the blocks are added into the error set; S4, repeating S3 until the error set is 0, and turning to S5; and S5, carrying out all the following rounds according to the S2 to S4.