The invention discloses a vertical air conditioner indoor unit. The vertical air conditioner indoor unit comprises an upper shell and a lower shell. A cylindrical cavity is defined by the lower shell. The lower shell contains an annular evaporator and at least one fan. The lower shell is provided with an air inlet, and the upper shell is provided with an air outlet/air outlets. The cross section area of the upper shell is gradually reduced to a fixed value from bottom to top, and the air outlet/the air outlets is/are formed in one side or two reverse sides of the upper shell and extends/extend in the vertical direction.