The employment of solar multistage distillers possessing thermal localization and energy cycle properties for saltwater desalination exhibits significant potential in fulfilling the increasing worldwide need for freshwater. In order to prevent salt crystallization on evaporators, most evaporators, however, excessively boost brine exchanging in distiller while ignoring heat loss during water convection. Here, we introduce an interesting porous aerogel-based multistage distiller (PAMS) that effectively suppresses heat loss during saltwater exchanging by controlling the water absorption rate through pore structure devising. This allows us to optimize the balance between evaporation, water transport, and salt-crystallization resistance. Finally, PAMS can reach a remarkable evaporation rate of 5.93 kg m−2h−1 and a high water-collection rate of 4.03 kg m−2h−1 under one solar irradiation thanks to the adjustable balance. Besides, PAMS exhibits impressive long-term stable antibacterial properties, which enhances the anti-biofouling and increases its reliability as a source of freshwater for ocean farm.