A series of pervaporation (PV) hybrid membranes were prepared via the crosslinking of poly(vinyl alcohol) with formaldehyde solution with N-3-(trimethoxysilyl) propyl ethylenediamine (TMSPEDA) as a hybrid precursor of the sol-gel process. Both the thermal stability and separation performances of the prepared hybrid membranes were investigated. Thermogravimetric analysis showed that the thermal degradation temperature of the hybrid membranes was beyond 250 C. Differential scanning calorimetry indicated that both the glass-transition temperature and the crystallization temperature increased with elevated TMSPEDA contents in the hybrid membranes. PV experiments demonstrated that for membranes A-D, both the permeation flux and separation factor indicated the same trade-off effect. Moreover, it was found that for individual membranes, the permeation flux increased as the feed temperature was increased. Meanwhile, the separation factor revealed an change trend opposite to that of the permeation flux. Furthermore, proper addition of TMSPEDA in the hybrid membrane was found to reduce the permeation activation energy. On the basis of these findings, we deduced that these hybrid membranes have potential applications in the separation of methanol/water mixtures.