A new type of biochar-SiO2 core-shell particles (BCNPs) was successfully prepared via the sol-gel-sediment method. The characteristics of BCNPs were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). This novel filler was added to a polydimethylsiloxane (PDMS) matrix to prepare composite membranes to separate ethanol from water via pervaporation (PV). The effect of BCNPs on the performance of the membranes was researched. Experimental results showed that the addition of BCNPs led to remarkably improved PV performance of composite membranes. When a BCNPs content was 5 wt.% for a 10 wt.% ethanol solution at 40 °C, the best PV performances gained were the separation factor of 11.9 and the corresponding permeation flux of 227 g·m-2·h-1.