Disclosed are a method and an apparatus for implementing privacy amplification in quantum key distribution. Participants of the quantum key distribution include a first participant and a second participant, which share a first key pool including at least one key. The method is executed on a terminal of either of the first and second participants, and includes: acquiring an auxiliary string to be used in current privacy amplification processing, wherein the auxiliary string is determined based on a seed key determined from the first key pool and a first Hash function agreed with the other participant; acquiring, in a stream way, at least one first bit in a first key subjected to information reconciliation; and performing a preset inter-bit operation between the at least one first bit and bits at corresponding positions in the auxiliary string to obtain at least one second bit for forming a privacy-amplified second key.