There is provided a liquid water harvester based on a valve-controlled active air supply and belongs to the field of liquid water harvesters. The present disclosure aims to address the problem of low airflow speed, high environmental humidity requirements, and auxiliary heating of an adsorption stage in the current atmospheric water harvesting technologies. In the present disclosure, the active air supply device is used to speed up the air circulation in the harvester so as to greatly shorten the adsorption time of the moisture absorbing material for the water vapor in the air and improve the heat dissipation of the micro-nano structure condensation surface. The electric valve controls the air circulation circuit and cooperates with the active air supply device. In this case, only one active air supply device can be used to complete the air supply and the condensation heat dissipation at the same time.