Potassium-ion　batteries　(KIBs)　are　highly　considered　as　the　leading　choice　for　grid-level　energy　storage　systems　owing　to　their　low　price　and　vast　potassium　reserves.　In　pursuit　of　better　battery　performance,　metal　phosphides　are　explored　as　promising　high　capacity　anode　materials　for　KIBs,　which　are　nevertheless　still　plagued　by　inferior　electronic　conductivity　and　considerable　volumetric　changes　during　repeated　potassiation/depotassiation　cycles.　As　a　qualified　case　to　fully　utilize　the　advantages　of　metal　phosphides　while　meanwhile　conquering　their　major　drawbacks,　we　present　this　rationally　engineered　hollow　FeP　nanoparticle　anchored　three-dimensional　porous　carbon　(h-FeP@3D-PC)　composite　for　performance-enhanced　KIBs.　The　rigid　honeycomb-like　3D-PC　scaffold　with　a　substantially　interconnected　porous　structure　not　only　enables　sufficient　electrolyte　infiltration　and　accelerated　ion/electron　transport,　but　also　provides　spatial　confinements　to　repress　unwanted　agglomeration　and　buffer　mechanical　strain　of　hollow　FeP　nanospheres　accompanied　by　potassiation,　thereby　shaping　a　more　efficient　and　robust　electrode.　Consequently,　this　meticulously　designed　h-FeP@3D-PC　demonstrates　remarkable　electroactivity　for　potassium-ion　storage　in　terms　of　superior　capacity　(343.5　mA　h　g(-1)　at　50　mA　g(-1))　and　a　prolonged　lifespan　with　a　high　value　retention　of　172　mA　h　g(-1)　after　2000　loops　at　0.8　A　g(-1),　indicating　great　promise　for　actual　applications.