The invention discloses a heat exchanger assembly and an indoor unit of an air conditioner, wherein the heat exchanger assembly is used for the indoor unit of the air conditioner. The heat exchanger assembly is characterized by comprising a main heat exchanger, wherein the main heat exchanger comprises a front heat exchanger, a middle heat exchanger and a rear heat exchanger, wherein the front heat exchanger, the middle heat exchanger and the rear heat exchanger are both provided with at least two rows of heat exchange tubes and the number of the heat exchange tubes of the middle heat exchanger is more than that of the front heat exchanger and the rear heat exchanger, and a back pipe heat exchanger. The heat exchange flow path of the heat exchanger assembly is divided into a first branch,a second branch and a third branch after passing through the back pipe heat exchanger, and the first branch, the second branch and the third branch all flow from the heat exchange tube on the windwardside of the main heat exchanger to the heat exchange tube on the leeward side. The first branch flows through the heat exchange tubes of the front heat exchanger, the second branch flows through theheat exchange tubes of the middle heat exchanger, the third branch flows through the heat exchange tubes of the rear heat exchanger, and at least one of the first branch and the third branch is arranged across the heat exchange tubes of the middle heat exchanger. According to the technical scheme, the heat exchanger assembly can improve the energy efficiency of the heat exchanger.