The invention discloses a heat insulation material with nanometer pores and a manufacturing method thereof; the heat insulation material with nanometer pores is prepared from the following components: silica of nanometer level, silicon source sol, inorganic reinforced fiber, structural strengthening agent, surface modifier, sunscreen, catalyst and diluents. The heat insulation material with nanometer pores prepared by the invention can be easily shaped, with small bulk density, small thermal conductivity, high utilization temperature, non-combustible performance, and certain mechanical strength; the interspace of the nanometer pores is over 80 percent, and the bulk density is from 150 to 250kg/m<3>; the thermal conductivity under room temperature is less than 0.025W/m.k, and the average thermal conductivity under 500 DEG C is no more than 0.050W/m.k, with the highest utilization temperature 950 DEG C; the invention is suitable for heat insulation in boats, industrial pipes and heating furnaces.