A low-density compound heat insulation metal material comprises a metal heat insulation layer, a protection layer, a noise reduction layer and a heatproof layer from inside to outside; the metal heat insulation layer adopts a stainless steel plate material, and is formed through lamination hot rolling of the stainless steel plate material and a titanium alloy plate; the titanium alloy plate is pre-doped with silicon carbide; and the protection layer adopts an aluminum foil layer processing technology, the noise reduction layer is used for reducing extraneous noise interference, and the heatproof layer is used for protecting the metal heat insulation layer, the protection layer and the noise reduction layer. The low-density compound heat insulation metal material adopts scientific and optimized structure design, and has high heat insulation effect and optimal cost performance due to adoption of optimal component fusion obtained after experiments; the low-density compound heat insulation metal material can realize safe and environmentally-friendly heat insulation effects, and also has certain noise reduction ability and high safety coefficient; and optimized composite layer-layer structure design greatly prolongs the service life of the low-density compound heat insulation metal material and reduces the occurrence probability of safety accidents.