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　PM(0.3　)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　(approximate　to　120　nm)　and　micro-beads　(approximate　to　3.37　mu　m)　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　&　sdot;s(-1),　and　water　vapor　transmission　of　7.6　kg　&　sdot;m(-2)&　sdot;d(-1).　This　work　may　offer　a　novel　insight　for　exploiting　high-performance　and　comfortable　personal　protective　materials.