In this paper, the low molecular weight poly(p-phenylene terephthalamide) (PPTA) was introduced into the surface of integral PE network by a dip-coating and phase separation process, and a thermally stable separator with thermal-shutdown function was prepared. The pore structure of PE separator was primely retained by controlling the concentration of the casting solution. The composite separator was proved to combine thermal shutdown function and exceptional thermal stability higher than 240 degrees C. The polar PPTA coating and remained pore structure endowed composite separator with superior wettability, ionic conductivity and cell performance. Remarkably, the facile procedure, lower cost and excellent properties can satisfy the stringent demand of industrialization for high-performance lithium ion batteries.