Large quantities of basic waste residue were drained from paper mills and sugar refineries every year, resulting in the pollution of the environment. The preparation of light_duty thermal insulation material by mixing bentonite with solid waste residue is of great social and economic significance. In this research, such characteristics of bentonite as ion exchange, adsorption,dispersion and special structure were used. The waste residue with bentonite and pearlite was mixed and sintered below 1050℃. The light thermal insulation material was made by bentonite and industrial waste residue. This is a solid phase reaction. The effects of bentonite, size, temperature and time were studied. The best technology includes size 600~800μm, SiO2∶CaO= 1∶1, temperature 1000~1050℃, and sintering time 4~6 hours. The experimental results are heat conduction coefficient 0.171 W/m·K, compressive strength 9.37 kg/cm2, and unit weight 0.49 g/cm3. The function of the product has reached or surpassed the synthesized product. The main component isβ_CaSiO3, together with small amounts of nephelite and wollastonite. Studies show that the heat effect of bentonite helps reaction at high temperature. With- out producting new pollution, the reaction can not only handle waste residue but also turn the harmful into the beneficial.