Chopped mullite fiber porous skeleton was sintered at 1260℃ by colloidal silica and B₄C powders. Then Porous skeleton was loaded with silica-sols prepared by tetraethyloxylane(TEOS), deionized water and ethanol. Silica-aerogels loading chopped mullite fiber porous skeleton was achieved by supercritical drying. Via thermogravimetry(TG), differential thermal analysis(DTA) and energy dispersive spectrometry(EDS), it was revealed that at 700℃～900℃, B₄C was oxidized into B₂O₃ which bound chopped fibers. Furthermore, chopped mullite fiber porous skeleton was chemically stable below 1500℃. Insulation tiles possessed nanoporous structure since silica-aerogels filled microporous pores of chopped mullite fiber skeleton. Thus thermal conductivity of insulation tiles was reduced by 44.3%, 33.8%, 34.6%, 29.5% at 300℃, 500℃, 800℃ and 1000℃ respectively. Besides, the loading of silica-aerogels improved flexural strength and compressive strength of porous skeleton at 50% and 40%, respectively.