An air conditioner indoor unit, comprising: a back plate component; a top cover component, a part of the top cover component being connected to a top wall of the back plate component; a panel component, the panel component comprising: a first panel, a top end of the first panel is connected to another part of the top cover component, the first panel being arranged in front of the back plate component and connected to the back plate component, the first panel being provided with a first air outlet and a second air outlet arranged in sequence in an up and down direction, characterized in that the panel component further comprises: a second panel disposed below the first panel, and connected to a lower end of the first panel and the back plate component, respectively, and the second panel and the first panel being independently processed and molded; an opening and closing door mounting plate disposed at the rear of the first panel, and provided with a guiding groove extending in the up and down direction; an opening and closing door arranged between the first panel and the opening and closing door mounting plate, the opening and closing door being movable upwardly and downwardly relative to the opening and closing door mounting plate so as to open or close the first air outlet, a guiding post being arranged on the opening and closing door and configured to extend into the guiding groove, and the guiding post being slidable relative to the guiding groove. a back plate component; a top cover component, a part of the top cover component being connected to a top wall of the back plate component; a panel component, the panel component comprising: a first panel, a top end of the first panel is connected to another part of the top cover component, the first panel being arranged in front of the back plate component and connected to the back plate component, the first panel being provided with a first air outlet and a second air outlet arranged in sequence in an up and down direction, characterized in that the panel component further comprises: a second panel disposed below the first panel, and connected to a lower end of the first panel and the back plate component, respectively, and the second panel and the first panel being independently processed and molded; an opening and closing door mounting plate disposed at the rear of the first panel, and provided with a guiding groove extending in the up and down direction; an opening and closing door arranged between the first panel and the opening and closing door mounting plate, the opening and closing door being movable upwardly and downwardly relative to the opening and closing door mounting plate so as to open or close the first air outlet, a guiding post being arranged on the opening and closing door and configured to extend into the guiding groove, and the guiding post being slidable relative to the guiding groove. a second panel disposed below the first panel, and connected to a lower end of the first panel and the back plate component, respectively, and the second panel and the first panel being independently processed and molded; an opening and closing door mounting plate disposed at the rear of the first panel, and provided with a guiding groove extending in the up and down direction; an opening and closing door arranged between the first panel and the opening and closing door mounting plate, the opening and closing door being movable upwardly and downwardly relative to the opening and closing door mounting plate so as to open or close the first air outlet, a guiding post being arranged on the opening and closing door and configured to extend into the guiding groove, and the guiding post being slidable relative to the guiding groove.