Particulate　matter　(PM)　pollution　causes　critical　harm　to　human　health　and　global　environment.　However,　the　protective　respirators　attain　high-performance　filtration　of　the　most　permeable　PM0.3　by　tight　stacking　of　fibers　and　seriously　compromising　their　wearing　comfort.　Herein,　a　fluffy　sandwich-structured　membrane　(SSM)　composed　of　bimodal　fibrous　layers　and　bead-on-string　fibrous　layer　is　designed　to　endow　the　air　filter　with　both　high-performance　filtration　and　superior　thermal-wet　comfort.　Based　on　the　electrospinning　technique,　the　bimodal　fibers　made　of　nano-/submicron-fibers　(about　46　nm　and　155　nm)　are　formed　by　inducing　the　jet　splitting　while　the　bead-on-string　fibers　consisting　of　submicron-fibers　(≈　120　nm)　and　micro-beads　(≈　3.37　μm)　are　prepared　through　manipulating　the　Rayleigh　instability　of　jets.　Due　to　the　structural　design　of　small　pores　and　low　packing　density,　the　SSM　exhibits　excellent　PM0.3　removal　of　99.8%,　low　filtration　resistance　of　65　Pa,　and　high　quality　factor　of　0.097　Pa-1.　It　also　shows　long-term　filtration　stability　and　durability　under　high　humidity　conditions.　Moreover,　the　SSM　simultaneously　possesses　superior　thermal-wet　comfort　of　heat　dissipation,　air　permeability　of　164　mm·s-1,　and　water　vapor　transmission　of　7.6　kg·m-2·d-1.　This　work　may　offer　a　novel　insight　for　exploiting　high-performance　and　comfortable　personal　protective　materials.　©　2024　Elsevier　B.V.