The specimens were prepared with high alumina fiber accounting for 0, 5%, 10% or 15% by mass of the total amount of amorphous silica and high alumina fiber, using phenolic resin as binder, and extra-adding 0 or 0.5% ZnO as sunscreen to cut the cost of SiO2 nanoporous insulation board. The hot volume stability and thermal conductivity (flat plate method) of the specimens were tested and multi-function simulation equipment was used to study the thermal insulation performance. The results show that: (1) with high alumina fiber addition increasing, the linear shrinkage rate decreases, but thermal conductivity changes a little; (2) adding ZnO can decrease thermal conductivity obviously; (3) for the specimen with ZnO and 15% of high alumina fiber, its cold face temperature hardly rises during the simulation experiment at 1 000 ℃ for 2 h, and the cold face temperature of the specimen with the smallest thickness of 2 cm doesn’t exceed 180 ℃.