The invention relates to heat-insulating foam paper. The heat-insulating foam paper comprises an intermediate paper base layer, an inner lamination layer and an outer lamination layer, and is characterized in that the inner lamination layer adopts an LDPE/HDPE/LDPE three-layer coextruded lamination layer; the three layers of co-extruding materials are in the mass consumption ratio of 1:3-4:1-4 inthe sequence from the paper base layer outwards; the raw material of the outer lamination layer is a blend material which comprises 60 to 80 percent of LDPE and 40 to 20 percent of POE plastics; the melt index of the LDPE plastic is 6.5 dg/min or above; the humidity gram weight proportion of the intermediate paper base layer is controlled to be 7 to 11 percent. The heat-insulating foam paper has an excellent heat insulating effect, good and soft hand feeling and strong velvet feeling, is easy to bind in post processing and forming, and is suitable for industrial production.