The invention discloses a method for machining a multi-layer thermal insulation material retainer. The method utilizes moso bamboos to produce long bamboo strips, short bamboo strips, a large bamboo ring and a small bamboo ring, which are fixedly assembled on a machined top ring, and after high-temperature heat treatment and punching, the multi-layer thermal insulation material retainer is produced. The method can ensure that when temperature is overlow or overhigh, the multi-layer thermal insulation material retainer can prevent a multi-layer thermal insulation material from failing due to separation, and moreover, the requirement on weight can be effectively decreased.