An air conditioner indoor unit includes a chassis and a face frame. The chassis extends along an up-down direction and includes a plurality of fastening structures arranged at upper end of the chassis and spaced along a left-right direction. The face frame includes an upper support, a lower frame, and two side connectors opposite to each other and connected between the upper support and the lower frame. The upper support includes a fastening member arranged at a rear end of the upper support. The fastening member is detachably fastened to the upper end of the chassis. The lower frame is detachably connected to a lower end of the chassis.