In view of the distribution ban of fluorine-containing waterproofing agents in recent years, the development of environment-friendly fluorine-free waterproofing agents with excellent waterproof performance has become a key issue in the field of fabric finishing. The existing strategies based on the combination of long chain alkane and low surface energy silicone with nanoparticles are limited by the poor hydrophobicity and wear resistance, which seriously restrict the development and application of this kind of waterproofing agent. In this work, n-hydroxymethyl acrylamide (N-MAM) was introduced and combined with octadecene (ODE) and vinyl-terminated polydimethylsiloxane (Vi-PDMS) to achieve tough bonding between the low surface energy polymer network and the fabric surface via self-crosslinking and interface crosslinking of n-hydroxymethyl. The finished fabric is endowed with excellent mechanical and chemical stability, including waterproof, air permeability, abrasive resistance, acid and alkali resistance, washing resistance. The water contact angle on the surface of the treated fabric is up to 157° and the treated fabric remains good hydrophobicity after 1000 times of mechanical pressure friction, 10 minutes of strong acid and alkali immersion, and 5 cycles of washing. The flourine-free waterproofing agent has little effect on air permeability of the fabric, and the air permeability reaches 697 mm/s and 720 mm/s respectively before and after treatment, which solves the problem with traditional coated waterproof fabrics that are hydrophobic but not air permeable.