Direct solar steam generation (DSSG) is well-proven to be a sustainable and effective technique to provide high-quality freshwater supply. However, it customarily suffers from severe salt accumulation, especially for treating strong brine, becoming a fatal bottleneck for approaching its commercial applications. Herein, we developed a DSSG with potent siphon-drop mode to achieve powerful self-absorbing and self-desalting, in which the 3D cone-shaped self-supporting polydopamine and polyethyleneimine co-coated poly(acrylonitrile-styrene-acrylate) (PDA-PEI@ASA) used as photothermal material (PTM). Source water can be spontaneously and continuously pumped to the top of water-evaporating surface of PTM via strong siphon effect, and the top-down active water diffusion on evaporating surface can effectively take the salts away from the system. Such above features give the DSSG real-time antifouling nature and hence address the fatal issue of salt accumulation. Accordingly, when continuously treating a near-saturated brine (20% NaCl) for at least 168 h, no obvious salts deposition can be found with a steady water evaporation rate of ∼2.550 kg m^–2 h⁻¹. This work could help shed novel light on the design of practical DSSG systems toward efficient lasting freshwater extraction, holding great promise for global water scarcity.

直接太阳能蒸汽发电 (DSSG) 已被充分证明是一种可持续且有效的技术，可提供高质量的淡水供应。然而，它通常会出现严重的盐分积累，特别是在处理浓盐水时，成为其商业应用的致命瓶颈。在此，我们开发了一种具有强虹吸模式的 DSSG 以实现强大的自吸和自脱盐，其中 3D 锥形自支撑聚多巴胺和聚乙烯亚胺共涂聚（丙烯腈-苯乙烯-丙烯酸酯）（PDA- PEI@ASA）用作光热材料（PTM）。源水可自发地和连续泵送至PTM的水蒸发表面的顶部通过虹吸作用强，蒸发面上自上而下的主动水扩散能有效地将盐分带离系统。上述这些特性赋予 DSSG 实时防污特性，从而解决盐分积累的致命问题。因此，当连续处理近饱和盐水（20% NaCl）至少 168 小时时，不会发现明显的盐沉积，稳定的水蒸发速率约为 2.550 kg m ^–2 h ^-1。这项工作有助于为实用的 DSSG 系统的设计提供新的思路，以实现高效、持久的淡水提取，为全球水资源短缺带来巨大希望。