A packet loss detection method includes: a receiving end receives a service packet whose color belongs to a first color spectrum; counts the number of the service packets whose color belongs to the first color spectrum; after receiving a detection packet, continues counting the number of the service packets whose color belongs to the first color spectrum, where the detection packet carries the number of service packets whose color belongs to the first color spectrum and that are sent by a sending end; when a preset condition is satisfied, the receiving end stops counting the number of the service packets whose color belongs to the first color spectrum, where the number of the service packets counted by the receiving end and the number of the service packets sent by the sending end carried in the detection packet are used for calculating the number of lost packets.