On-line cleaning and drying method of hollow fiber hydrophobic membrane module

The invention relates to an on-line cleaning and drying method of a hollow fiber hydrophobic membrane module. The on-line cleaning and drying method comprises the following steps of 1, carrying out switching from a membrane module which runs for specific time and needs to be cleaned to another membrane module which does not need to be cleaned, 2, carrying out on-line front washing on the membrane module needing to be cleaned by tap water for a certain time, 3, carrying out on-line back washing on the membrane module needing to be cleaned by tap water for a certain time, 4, carrying out on-line drying on the membrane module subjected to front washing and back washing, and 5, placing the dried membrane module at a position for next use. The on-line cleaning and drying method realizes hydrophilization penetration of a hydrophobic membrane module in membrane distillation, prevents hydrophobic membrane module severe hydrophilization-caused seepage of the hydrophobic membrane module, prevents fast hydrophilization of the hydrophobic membrane module, delays hydrophilization tendency of the hydrophobic membrane module and prolongs a service life of the hydrophobic membrane module. The on-line cleaning and drying method guarantees membrane distillation product water mass in membrane distillation, has simple processes and can be operated easily.