Air conditioner indoor unit and air conditioner

The invention provides an air conditioner indoor unit and an air conditioner. The air conditioner indoor unit comprises a shell provided with a first air inlet, a second air inlet, an air outlet and a main air duct, and the main air duct communicates with the first air inlet and the air outlet; the fresh air device is arranged in the shell, the air inlet end of the fresh air device communicates with the second air inlet, and the air outlet end of the fresh air device communicates with the main air duct; the fresh air device is configured to be capable of guiding the flow direction of part of airflow flowing through the main air duct, so that part of airflow diffuses and flows towards the air outlet. When the fresh air device works, fresh air flows out of the air outlet end of the fresh air device, and a negative pressure area is formed at the air outlet end of the fresh air device under the ejection action of the fresh air, so that part of airflow of the main air duct is guided, part of airflow diffuses and f