A cabinet, comprising: a cabinet body, wherein a first-stage temperature control component configured to control a temperature of the cabinet body is disposed on the cabinet body, and at least one temperature control capacity expansion interface that may be used to connect a second-stage temperature control component and the cabinet body, is disposed on the cabinet body, so that the second-stage temperature control component is disposed on the cabinet body in an expandable manner, and the second-stage temperature control component and the first-stage temperature control component form a circulating cooling air duct in the cabinet body, so that hot air in the cabinet body passes through the first-stage temperature control component for cooling, and then enters the second-stage temperature control component for cooling; wherein the cabinet further comprises the second-stage temperature control component, wherein the second-stage temperature control component is disposed on the cabinet body through the temperature control capacity expansion interface; wherein a first internal circulation air duct and a first external circulation air duct are disposed in the first-stage temperature control component, a second internal circulation air duct and a second external circulation air duct are disposed in the second-stage temperature control component, an air intake vent and an air exhaust vent of the first internal circulation air duct and an air intake vent and an air exhaust vent of the second internal circulation air duct each communicate with internal space in the cabinet body, and the air exhaust vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct are disposed opposite to each other, so that cold air obtained after cooling in the first internal circulation air duct enters the second internal circulation air duct for cooling again; wherein an internal circulation fan is disposed at each of the air intake vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct, such that the hot air in the cabinet is sucked into an internal circulation air duct through the air intake vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct under an action of the internal circulation fan for cooling. a cabinet body, wherein a first-stage temperature control component configured to control a temperature of the cabinet body is disposed on the cabinet body, and at least one temperature control capacity expansion interface that may be used to connect a second-stage temperature control component and the cabinet body, is disposed on the cabinet body, so that the second-stage temperature control component is disposed on the cabinet body in an expandable manner, and the second-stage temperature control component and the first-stage temperature control component form a circulating cooling air duct in the cabinet body, so that hot air in the cabinet body passes through the first-stage temperature control component for cooling, and then enters the second-stage temperature control component for cooling; wherein the cabinet further comprises the second-stage temperature control component, wherein the second-stage temperature control component is disposed on the cabinet body through the temperature control capacity expansion interface; wherein a first internal circulation air duct and a first external circulation air duct are disposed in the first-stage temperature control component, a second internal circulation air duct and a second external circulation air duct are disposed in the second-stage temperature control component, an air intake vent and an air exhaust vent of the first internal circulation air duct and an air intake vent and an air exhaust vent of the second internal circulation air duct each communicate with internal space in the cabinet body, and the air exhaust vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct are disposed opposite to each other, so that cold air obtained after cooling in the first internal circulation air duct enters the second internal circulation air duct for cooling again; wherein an internal circulation fan is disposed at each of the air intake vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct, such that the hot air in the cabinet is sucked into an internal circulation air duct through the air intake vent of the first internal circulation air duct and the air intake vent of the second internal circulation air duct under an action of the internal circulation fan for cooling.