A washing and drying integrated machine, comprising a first drum (3, 4) and a second drum (1, 2) disposed in parallel, and a drying system, wherein the drying system comprises an air duct assembly, an air duct control device being disposed in the air duct assembly to conduct or cut off at least one of communication between the air duct assembly and the first drum (3, 4) and communication between the air duct assembly and the second drum (1, 2), so that a drying airflow is fed into the first drum (3, 4) or the second drum (1, 2) alone, or simultaneously fed into the first drum (3, 4) and the second drum (1, 2); wherein the drying system further comprises a fan assembly and a drying assembly, wherein the fan assembly is configured to generate an airflow, so as to feed heat generated by the drying assembly into at least one of the first drum (3, 4) and the second (1,2) via the air duct assembly; wherein the air duct assembly comprises a first air returning duct and a second air returning duct, the first air returning duct is configured to communicate the first drum (3, 4) and an air returning portion of the fan assembly, and the second air returning duct is configured to communicate the second drum (1, 2) and the air returning portion of the fan assembly; wherein the first air returning duct and/or the second air returning duct is configured to introduce cooling water, the cooling water is used to cool the wet and hot air from the first air returning duct and/or the second air returning duct, to convert the wet and hot air into dry air and condensed water; and wherein the washing and drying integrated machine further comprises a driving mechanism, the driving mechanism and the first drum (3, 4) are connected through a first transmission mechanism, and the driving mechanism and the second drum (1, 2) are connected through a second transmission mechanism, the first transmission mechanism and/or the second transmission mechanism is a transmission clutch (11, 12), and the first drum (3, 4) and the second drum (1, 2) are arranged in parallel in a vertical direction. wherein the drying system further comprises a fan assembly and a drying assembly, wherein the fan assembly is configured to generate an airflow, so as to feed heat generated by the drying assembly into at least one of the first drum (3, 4) and the second (1,2) via the air duct assembly; wherein the air duct assembly comprises a first air returning duct and a second air returning duct, the first air returning duct is configured to communicate the first drum (3, 4) and an air returning portion of the fan assembly, and the second air returning duct is configured to communicate the second drum (1, 2) and the air returning portion of the fan assembly; wherein the first air returning duct and/or the second air returning duct is configured to introduce cooling water, the cooling water is used to cool the wet and hot air from the first air returning duct and/or the second air returning duct, to convert the wet and hot air into dry air and condensed water; and wherein the washing and drying integrated machine further comprises a driving mechanism, the driving mechanism and the first drum (3, 4) are connected through a first transmission mechanism, and the driving mechanism and the second drum (1, 2) are connected through a second transmission mechanism, the first transmission mechanism and/or the second transmission mechanism is a transmission clutch (11, 12), and the first drum (3, 4) and the second drum (1, 2) are arranged in parallel in a vertical direction.