Superhydrophobic materials used for oil‐water separation have received wide attention. However, the simple and low‐cost strategy for making durable superhydrophobic materials remains a major challenge. Here, we report that stable and durable superhydrophobic cotton fabrics can be prepared using a simple two‐step impregnation process. Silica nanoparticles are surface modified by hydrolysis condensation of 3‐aminopropyltrimethoxysilane (APTMS). The amino group of APTMS and the acrylic group of the crosslinking agent pentaerythritol triacrylate (PETA) undergo 1,4‐conjugate addition reaction to fix the silica nanoparticles, and the acrylic group of the crosslinking agent PETA undergo 1,4‐conjugate addition reaction with the amino group of octadecylamine (ODA), finally forming a covalent cross‐linked rough network structure. The long hydrophobic chain of ODA makes the cotton fabric exhibit excellent superhydrophobic properties, and the water contact angle (WCA) of the fabric surface reaches 158°. The modified cotton fabric has good physical and chemical stability, self‐cleaning and anti‐fouling. At the same time, the modified fabric shows excellent oil/water separation efficiency (98.16% after 20 cycles) and ultrahigh separation flux (15413.63 L m−2 h−1) due to its superhydrophobicity, superoleophilicity and inherent porous structure. The method provides a broad prospect in the future diversification applications of oil/water separation and oil spill cleaning.This article is protected by copyright. All rights reserved