To overcome the two main obstacles of large-scale application of superspreading material, self-assembly was used to prepare superspreading polymer membrane (SPPM) in this work. An amphiphilic SPPM was prepared by capillary force-driven self-assembly using PP melt-blown nonwovens and polyvinyl alcohol (PVA). The prepared SPPM has low preparation cost and stable performance since self-assembly needs low energy consumption, and the production is thermodynamically stable. By using Cryo-TEM, TEM, XPS and SEM with EDS element analysis, it was proved that PVA have been successfully assembled on the fiber surface of PP melt-blown nonwovens. The prepared SPPM has excellent spreading performance, the "spreading times" of both water and oil are less than 0.5 seconds. They showed much superior performance compared to traditional materials when applied in oil-water separation, seawater desalination and ion separation. This work will definitely promote the development of self-assembly, superspreading materials and related sciences. This article is protected by copyright. All rights reserved.