An air conditioner cabinet, comprising: a housing, wherein the housing is provided with an upper air port and a lower air port; a mixed flow fan, wherein the mixed flow fan is disposed in the housing; and a regulating mechanism, wherein the regulating mechanism is disposed in the housing, the regulating mechanism has a necking position and a flaring position, and when the regulating mechanism is located at the necking position, the mixed flow fan sucks an external airflow into the housing from the upper air port, and then discharges the external airflow from the housing by the lower air port; characterised in that: a heat exchanger, wherein the heat exchanger is disposed in the housing and is located between the upper air port and the lower air port, the regulating mechanism is located between the mixed flow fan and the heat exchanger, the regulating mechanism has the necking position where the regulating mechanism contracts toward an axis of the housing, the regulating mechanism has the flaring position where the regulating mechanism gradually expands away from the axis of the housing, and when the regulating mechanism is located at the necking position, the mixed flow fan sucks the external airflow into the housing from the upper air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the lower air port; wherein when the regulating mechanism is located at the flaring position, the mixed flow fan sucks the external airflow into the housing from the lower air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the upper air port. a housing, wherein the housing is provided with an upper air port and a lower air port; a mixed flow fan, wherein the mixed flow fan is disposed in the housing; and a regulating mechanism, wherein the regulating mechanism is disposed in the housing, the regulating mechanism has a necking position and a flaring position, and when the regulating mechanism is located at the necking position, the mixed flow fan sucks an external airflow into the housing from the upper air port, and then discharges the external airflow from the housing by the lower air port; characterised in that: a heat exchanger, wherein the heat exchanger is disposed in the housing and is located between the upper air port and the lower air port, the regulating mechanism is located between the mixed flow fan and the heat exchanger, the regulating mechanism has the necking position where the regulating mechanism contracts toward an axis of the housing, the regulating mechanism has the flaring position where the regulating mechanism gradually expands away from the axis of the housing, and when the regulating mechanism is located at the necking position, the mixed flow fan sucks the external airflow into the housing from the upper air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the lower air port; wherein when the regulating mechanism is located at the flaring position, the mixed flow fan sucks the external airflow into the housing from the lower air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the upper air port. a heat exchanger, wherein the heat exchanger is disposed in the housing and is located between the upper air port and the lower air port, the regulating mechanism is located between the mixed flow fan and the heat exchanger, the regulating mechanism has the necking position where the regulating mechanism contracts toward an axis of the housing, the regulating mechanism has the flaring position where the regulating mechanism gradually expands away from the axis of the housing, and when the regulating mechanism is located at the necking position, the mixed flow fan sucks the external airflow into the housing from the upper air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the lower air port; wherein when the regulating mechanism is located at the flaring position, the mixed flow fan sucks the external airflow into the housing from the lower air port, so as to perform heat exchange with the heat exchanger, and then discharges the external airflow from the housing by the upper air port.