Automatic drying method of drum washing machine

The invention relates to an automatic drying method of a drum washing machine, which comprises the following steps: detecting the temperature T1 of a first temperature sensor in an air duct, detecting the temperature value T2 of a second temperature sensor in a drum, calculating the difference delta T between the two, calculating the slope of the delta T when the running time is larger than or equal to the set time 1, stopping heating during the drying process when the delta T is large than the limit value 1 delta Tmax and T1 is larger than the limit value 2 under the situation that the slope of the delta T is larger than the set value 1, and starting to cool till the end; or calculating the difference sigma between the temperature difference delta T and average value delta T0, stopping heating during the drying process if the order n that the sigma is larger than the reference value sigma 0 achieves the reference value n0 or the running time is larger than the set time 2, and starting to cool till the end. The automatic drying method can lead the judgment of drying to be more precise, lead the drying of clothes to be appropriate and prevent the clothes from being not dry or too dry during the drying.