The invention relates to an air conditioner indoor unit which comprises a unit shell. The unit shell is provided with a rear shell with an air inlet, and a front panel detachably installed on the front side of the rear shell. A lateral air outlet is formed in at least one transverse end portion of the unit shell is provided with. A heat exchange device is arranged in the unit shell. Each air outlet assembly is matched with one lateral air outlet and comprises a lateral air guide cylinder, wherein an air guide channel used for leading air to the corresponding lateral air outlet from the heat exchange device is formed in the lateral air guide cylinder, and a forward opening is formed in the front side of the lateral air guide cylinder. Ion air generation devices are inserted in the lateral air guide cylinders from the forward openings and are configured to promote air to flow towards the lateral air outlets through electric field force. Air purifying devices are inserted in the lateral air guide cylinders through the forward openings, located on the air outlet sides of the ion air generation devices, block the forward openings together with the ion air generation devices and are configured to remove harmful gas generated during running of the ion air generation devices. The air conditioner indoor unit is large in air supply range and low in noise, and the ion air generation devices and the air purifying devices are conveniently demounted and mounted.