The invention relates to a method for manufacturing a foamed thermal-insulation material from foam glass waste. The method is characterized by comprising the following steps: milling foam glass fragments and foam glass powder to form powder, uniformly stirring the powder with fly ash, a foam stabilizer, bamboo wood fibers, calcium stearate, oxydol, a foaming agent, an early-strength admixture, nano SiO2, cement, a foam stabilizer and water, and casting the mixture into a mold to form a rectangular block; and cutting the rectangular block into a regenerated thermal-insulation material sheet which is used as a middle layer, bonding foam glass side strips to the four sides, and bonding foam glass thermal-insulation sheets to the top and bottom as the upper layer and lower layer by using glue, thereby preparing the composite thermal-insulation board finished product.