Automatic cleaning system and method for filter screen of washing and drying machine and washing and drying machine

The invention discloses an automatic cleaning system and method for a filter screen of a washing and drying machine and the washing and drying machine, the system comprises a filter screen body, the filter screen body is installed between an air inlet section of a drying air duct of a washing and drying integrated machine and a heating system, and a cleaning device and an auxiliary air duct system are arranged on the side, away from the air inlet section, of the filter screen body; the cleaning device is used for washing impurities on the filter screen body to enable the impurities to be separated from the filter screen body, and the auxiliary air duct system is used for blowing air to the filter screen body, so that the filter screen body is in a dry and breathable state before the washing and drying all-in-one machine runs a drying procedure. On the basis of self-cleaning of the filter screen, the auxiliary air duct system is added, high-speed airflow is blown out during dewatering to blow the filter screen