The invention relates to a three-dimensional grid heat-insulation pad on the basis of weaving technologies and a method for preparing the three-dimensional grid heat-insulation pad, and is mainly applied to designing and manufacturing light heat-insulation pads. The three-dimensional grid heat-insulation pad and the method have the advantages that as discovered by theoretic and qualitative analysis on existing configuration, triangular siepinski fractural structures can be light on the premise that the strength, the rigidity and the stability are guaranteed, the contact areas of the air and heat sources can be enlarged, and good heat-insulation effects can be realized; three edges of each triangle are processed by the aid of the weaving technologies during practical analysis, accordingly,design ideas of further saving materials by integral devices can be implemented, the heat-insulation efficiency can be enhanced, and the flexibility of structures can be improved; the thickness of thethree-dimensional grid heat-insulation pad can be enlarged owing to multilayer overlaying designs, and the excellent heat-insulation effects can be realized even if the areas of the bottom surfaces of heat-insulation objects are larger than those of the triangles.