An indoor unit for an air conditioner, comprising: a swing assembly comprising a plurality of swing blades (1-1) parallel to each other, a first link (1-2), and a first mounting plate (1-3); and an air conditioner housing provided with an air outlet , wherein the plurality of swing blades (1-1) are spaced apart in a length direction of the first mounting plate (1-3), and all connected to the first link (1-2), the first link (1-2) is configured to drive the swing blades (1-1) to rotate about an axial direction, and the first mounting plate (1-3) is fixedly connected to the air outlet through a fixing mechanism, wherein a lower end of each swing blade (1-1) is provided with a fixing shaft (1-4), a middle portion of the fixing shaft (1-4) is provided with a connection portion (1-4-1), a lower end of the connection portion is provided with a conical head (1-4-2), a plurality of first grooves (1-4-2-1) are uniformity distributed at a lower end of the conical head (1-4-2) along a circumferential direction thereof, and the first mounting plate (1-3) is provided with a fixing shaft mounting hole (1-3-1) corresponding to the connection portion (1-4-1), wherein the first mounting plate (1-3) and the fixing shaft (1-4) are provided with a limit adjustment mechanism configured to prevent excessive rotation of the swing blade (1-1), characterized in that the limit adjustment mechanism comprises a second stopping rod (a2) provided at a periphery of the fixing shaft mounting hole (1-3-1) and fixedly connected to a lower surface of the first mounting plate (1-3), two third limit protrusions (b2) are provided on a side wall of the conical head (1-4-2) along a circumferential direction thereof, and the second stopping rod (a2) is rotatable between the two third limit protrusions (b2). a swing assembly comprising a plurality of swing blades (1-1) parallel to each other, a first link (1-2), and a first mounting plate (1-3); and an air conditioner housing provided with an air outlet , wherein the plurality of swing blades (1-1) are spaced apart in a length direction of the first mounting plate (1-3), and all connected to the first link (1-2), the first link (1-2) is configured to drive the swing blades (1-1) to rotate about an axial direction, and the first mounting plate (1-3) is fixedly connected to the air outlet through a fixing mechanism, wherein a lower end of each swing blade (1-1) is provided with a fixing shaft (1-4), a middle portion of the fixing shaft (1-4) is provided with a connection portion (1-4-1), a lower end of the connection portion is provided with a conical head (1-4-2), a plurality of first grooves (1-4-2-1) are uniformity distributed at a lower end of the conical head (1-4-2) along a circumferential direction thereof, and the first mounting plate (1-3) is provided with a fixing shaft mounting hole (1-3-1) corresponding to the connection portion (1-4-1), wherein the first mounting plate (1-3) and the fixing shaft (1-4) are provided with a limit adjustment mechanism configured to prevent excessive rotation of the swing blade (1-1), characterized in that the limit adjustment mechanism comprises a second stopping rod (a2) provided at a periphery of the fixing shaft mounting hole (1-3-1) and fixedly connected to a lower surface of the first mounting plate (1-3), two third limit protrusions (b2) are provided on a side wall of the conical head (1-4-2) along a circumferential direction thereof, and the second stopping rod (a2) is rotatable between the two third limit protrusions (b2). <EOS>