A powered device PD detection device, wherein the PD detection device comprises a detection circuit and a processing circuit, and the detection circuit is connected to the processing circuit; the detection circuit is configured to: receive hierarchical waveform information from power sourcing equipment, and generate a corresponding first-type signal or a corresponding second-type signal based on different voltages or duty cycles of the received hierarchical waveform information, wherein the first-type signal corresponds to first-type power sourcing equipment, the second-type signal corresponds to second-type power sourcing equipment, the first-type power sourcing equipment comprises non-standard power sourcing equipment or an adapter, and the second-type power sourcing equipment comprises AF power sourcing equipment, AT power sourcing equipment, or BT power sourcing equipment wherein AF, AT and BT power sourcing equipment are power sourcing equipments that conform to the PoE standards IEEE802.3 af, IEEE802.3 at and IEEE802.3 bt respectively; the processing circuit is configured to: determine, based on the first-type signal, that the power sourcing equipment is the first-type power sourcing equipment, or determine, based on the second-type signal, that the power sourcing equipment is the second-type power sourcing equipment; wherein the PD detection device further comprises a power adjustment circuit, wherein the power adjustment circuit is connected to the processing circuit, wherein the processing circuit is further configured to send a power adjustment signal to the power adjustment circuit based on a type of the power sourcing equipment, and wherein the power adjustment circuit is configured to perform power adjustment based on the power adjustment signal; wherein the power adjustment circuit comprises a power management unit and a service unit, wherein the power management unit is connected to the service unit, wherein the power management unit is configured to adjust an input signal of the service unit based on the power adjustment signal, and wherein the input signal comprises at least one of an input voltage and an input current; and wherein if the power sourcing equipment is the adapter, the power adjustment circuit is configured to adjust, based on the power adjustment signal, power of the service unit to maximum power allowed by the adapter. the detection circuit is configured to: receive hierarchical waveform information from power sourcing equipment, and generate a corresponding first-type signal or a corresponding second-type signal based on different voltages or duty cycles of the received hierarchical waveform information, wherein the first-type signal corresponds to first-type power sourcing equipment, the second-type signal corresponds to second-type power sourcing equipment, the first-type power sourcing equipment comprises non-standard power sourcing equipment or an adapter, and the second-type power sourcing equipment comprises AF power sourcing equipment, AT power sourcing equipment, or BT power sourcing equipment wherein AF, AT and BT power sourcing equipment are power sourcing equipments that conform to the PoE standards IEEE802.3 af, IEEE802.3 at and IEEE802.3 bt respectively; the processing circuit is configured to: determine, based on the first-type signal, that the power sourcing equipment is the first-type power sourcing equipment, or determine, based on the second-type signal, that the power sourcing equipment is the second-type power sourcing equipment; wherein the PD detection device further comprises a power adjustment circuit, wherein the power adjustment circuit is connected to the processing circuit, wherein the processing circuit is further configured to send a power adjustment signal to the power adjustment circuit based on a type of the power sourcing equipment, and wherein the power adjustment circuit is configured to perform power adjustment based on the power adjustment signal; wherein the power adjustment circuit comprises a power management unit and a service unit, wherein the power management unit is connected to the service unit, wherein the power management unit is configured to adjust an input signal of the service unit based on the power adjustment signal, and wherein the input signal comprises at least one of an input voltage and an input current; and wherein if the power sourcing equipment is the adapter, the power adjustment circuit is configured to adjust, based on the power adjustment signal, power of the service unit to maximum power allowed by the adapter.