A power adapter , wherein the power adapter comprises: a housing , wherein the housing has an air inlet and an air outlet and the housing comprises a first surface and a second surface that are disposed opposite to each other; a circuit board component , wherein the circuit board component is located inside the housing ; and a heat dissipation air duct , wherein the heat dissipation air duct is located in the housing , and wherein the heat dissipation air duct is a spacing area between the housing and the circuit board component , or the combination of the housing and a spacing area between the housing and the circuit board component , wherein the heat dissipation air duct surrounds the circuit board component and is connected to the air inlet and the air outlet , and the heat dissipation air duct is configured to dissipate heat from the housing , the circuit board component and the combination of the housing and the circuit board component , whereas the power adapter further comprises a first pin and a second pin , characterized in that a first accommodation groove for accommodating the first pin and a second accommodation groove for accommodating the second pin are disposed on the first surface , and the first accommodation groove and the second accommodation groove are disposed at intervals; and the air inlet is disposed on a groove wall of the first accommodation groove, and the air outlet is disposed on a groove wall of the second accommodation groove or the air inlet is disposed on the second surface , the air outlet comprises a first sub-air outlet and a second sub-air outlet , the first sub-air outlet is disposed on a groove wall of the first accommodation groove , and the second sub-air outlet is disposed on a groove wall of the second accommodation groove . a housing , wherein the housing has an air inlet and an air outlet and the housing comprises a first surface and a second surface that are disposed opposite to each other; a circuit board component , wherein the circuit board component is located inside the housing ; and a heat dissipation air duct , wherein the heat dissipation air duct is located in the housing , and wherein the heat dissipation air duct is a spacing area between the housing and the circuit board component , or the combination of the housing and a spacing area between the housing and the circuit board component , wherein the heat dissipation air duct surrounds the circuit board component and is connected to the air inlet and the air outlet , and the heat dissipation air duct is configured to dissipate heat from the housing , the circuit board component and the combination of the housing and the circuit board component , whereas the power adapter further comprises a first pin and a second pin , characterized in that a first accommodation groove for accommodating the first pin and a second accommodation groove for accommodating the second pin are disposed on the first surface , and the first accommodation groove and the second accommodation groove are disposed at intervals; and the air inlet is disposed on a groove wall of the first accommodation groove, and the air outlet is disposed on a groove wall of the second accommodation groove or the air inlet is disposed on the second surface , the air outlet comprises a first sub-air outlet and a second sub-air outlet , the first sub-air outlet is disposed on a groove wall of the first accommodation groove , and the second sub-air outlet is disposed on a groove wall of the second accommodation groove . <EOS>