Fluorine-free　liquid-repellent　coatings　have　been　highly　demanded　for　a　variety　of　applications.　However,　rapid　formation　of　coatings　possessing　outstanding　oil　repellency　and　strong　bonding　ability　as　well　as　good　mechanical　strength　(e.g.,　bendability,　impact　resistance,　and　scratch　resistance)　remains　a　grand　challenge.　Herein,　a　robust　strategy　to　rapidly　create　fluorine-free　oil-repellent　coatings　in　only　30　s　via　rational　design　of　a　semi-interpenetrating　polymer　network　structure　is　reported.　The　resulting　coating　manifests　strong　bonding　capability　both　in　air　and　underwater.　More　importantly,　it　not　only　provides　unprecedented　oil　repellency,　even　to　high-viscosity　crude　oil,　but　also　achieves　both　excellent　bendability　and　hardness.　This　simple　yet　effective　design　strategy　opens　up　a　new　avenue　to　manufacture　multifunctional　materials　and　devices　with　desirable　features　and　structural　complexities　for　applications　in　sustainable　antifouling,　drag　reduction,　nondestructive　transportation,　liquid　collection,　and　biomedicine,　among　other　areas.　©　2022　Wiley-VCH　GmbH.