An in‐situ organic‐inorganic hybrid strategy is proposed for proton exchange membrane (PEM) preparation based on a hyperbranched polyamide proton conductive macromolecule. With similar effects on proton conductivity and methanol permeability as that of the conventional organic‐inorganic hybrid strategy, the in‐situ organic‐inorganic hybrid one showed much better retention capacity on mechanical stability. With trace amount of TiO2 nanoparticle, acting as a model inorganic filler in this work, methanol permeability of a previously developed macromolecular polyamide proton conductor, which already showed higher proton conductivity and methanol resistivity than the commercial Nafion membrane, is further reduced by ca. 20 % while the proton conductivity is only slightly decayed. More importantly, mechanical strength of the in‐situ hybrid membrane remained almost the same as that of the original polymeric membrane while the conventional hybrid strategy would lead to a 25 % tensile strength loss.