A packet loss detection method, comprising: receiving, by a receiving end, a service packet whose color belongs to a first color spectrum, wherein the color of the service packet is information used for identify the service packet, wherein the color of the service packet is at least one of an experiment field of an entropy label, a virtual local area network identifier, 802.1P and a sequence number of a pseudo wire control word; counting, by the receiving end, the number of the service packets whose color belongs to the first color spectrum, wherein the first color spectrum is a set of colors of a certain type of packets, wherein a set of colors of packets belonging to a same sending detection period is referred to as a color spectrum of the packets of the sending detection period, the sending detection period is a period that a sending end inserts a detection packet; after receiving a detection packet, continuing, by the receiving end, counting the number of the service packets whose color belongs to the first color spectrum, wherein the detection packet is different from the service packet, 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 within one sending detection period, color spectrums of service packets sent within two adjacent sending detection periods have no intersection, the color spectrums of the service packets sent within the two adjacent sending detection periods are the first color spectrum and a second color spectrum, wherein the first color spectrum does not comprise any color of the second color spectrum, and the second color spectrum does not comprise any color of the first color spectrum; when a preset condition is satisfied, stopping, by the receiving end, counting the number of the service packets whose color belongs to the first color spectrum, wherein the number of the service packets whose color belongs to the first color spectrum counted by the receiving end and the number of the service packets whose color belongs to the first color spectrum and that are sent by the sending end carried in the detection packet are used for calculating the number of lost packets; and calculating, by the receiving end, according to the counted number of the service packets whose color belongs to the first color spectrum and the number of the service packets whose color belongs to the first color spectrum and that are sent by the sending end carried in the detection packet, the number of lost packets for the service packets whose color belongs to the first color spectrum. receiving, by a receiving end, a service packet whose color belongs to a first color spectrum, wherein the color of the service packet is information used for identify the service packet, wherein the color of the service packet is at least one of an experiment field of an entropy label, a virtual local area network identifier, 802.1P and a sequence number of a pseudo wire control word; counting, by the receiving end, the number of the service packets whose color belongs to the first color spectrum, wherein the first color spectrum is a set of colors of a certain type of packets, wherein a set of colors of packets belonging to a same sending detection period is referred to as a color spectrum of the packets of the sending detection period, the sending detection period is a period that a sending end inserts a detection packet; after receiving a detection packet, continuing, by the receiving end, counting the number of the service packets whose color belongs to the first color spectrum, wherein the detection packet is different from the service packet, 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 within one sending detection period, color spectrums of service packets sent within two adjacent sending detection periods have no intersection, the color spectrums of the service packets sent within the two adjacent sending detection periods are the first color spectrum and a second color spectrum, wherein the first color spectrum does not comprise any color of the second color spectrum, and the second color spectrum does not comprise any color of the first color spectrum; when a preset condition is satisfied, stopping, by the receiving end, counting the number of the service packets whose color belongs to the first color spectrum, wherein the number of the service packets whose color belongs to the first color spectrum counted by the receiving end and the number of the service packets whose color belongs to the first color spectrum and that are sent by the sending end carried in the detection packet are used for calculating the number of lost packets; and calculating, by the receiving end, according to the counted number of the service packets whose color belongs to the first color spectrum and the number of the service packets whose color belongs to the first color spectrum and that are sent by the sending end carried in the detection packet, the number of lost packets for the service packets whose color belongs to the first color spectrum.