Based on a typical multilayer insulating materials in vacuum environment of series experiment and anlytical heat insulation performance,trend of multilayer insulation material layer temperature difference (Δt ) distribution was anlytical and the multilayer insulation materials in different interlayer insulation performance characteristics and their variation regularities was disdesed. The test results proved that multilayer insulation performance is superier to the intermediate layer heat insulation performance. Inside 4 layers and outside 18 layers air flow approach the molecular flow with better thermal insulating performance and big temperature difference(Δt ). The middle layer air flow is unsteady,and the insulation performance slightly differenct,temperature difference(Δt ) near the heating plate side is smaller, interpass temperature is less than the low temperature side.