Extrude type high density polystyrene froth heat preservation board, who possess the absolute airtight type air bubble structure, Therefore possessing the fine heat insulation and heat preservation capability, the good passes through the wet coefficient. Possessing the low thermal conductance coefficient, high resisted pressure, low inhales ability in water, that the low density foamed plastics ( EPS ) of tradition does not have, especially suitable in the heat insulation and dampproof engineering of the building, It is the highest material of cheap character of price in the building industry heat preservation heat insulation material.