A method of the present invention includes: determining, when packet congestion occurs or network bandwidth decreases, at least one to-be-discarded packet in a packet buffer; and discarding the at least one to-be-discarded packet so that at least one unbuffered packet enters the packet buffer to prevent discarding too many unbuffered packets, where the unbuffered packet is a packet that has not entered the packet buffer. The present invention is primarily applied in a packet buffering process.