The invention relates to a low-temperature curing low-surface-density functional composite surface adhesive film and a preparation method of the low-temperature curing low-surface-density functional composite surface adhesive film, and relates to the composite surface adhesive film and the preparation method of the composite surface adhesive film. To solve the problems of large density and high curing temperature of the existing composite surface adhesive film, the composite surface adhesive film is prepared from a solid epoxy resin, a liquid epoxy resin, a thermoplastics polymer, a curing agent, an accelerant, a talcum powder, fumed silica and a hollow glass microsphere. The preparation method is as follows: using the solid epoxy resin, the liquid epoxy resin and the thermoplastics polymer to prepare a mixed resin; mixing the mixed resin, the curing agent, the accelerant, the talcum powder, the fumed silica and the hollow glass microsphere in a kneading machine to form a surface filmadhesive material, extruding an adhesive film layer, and compounding with a conductive carrier layer. The composite surface adhesive film is cured within 120 minutes under the condition of 90 DEG C, the surface density is low, and the composite surface adhesive film has the electromagnetic shielding property and the lightning protection function. The preparation method is suitable for preparing the composite surface adhesive film.