The invention relates to a laminboard and further relates to a laminboard preparing method. Rolling and annealing destressing treatment is conducted on metal wires different in section size, metal wires with the spiral line square sections are manufactured, and lower spiral core unit cells are obtained; the initial angle of spiral lines is rotated by 180 degrees, the above technology process is repeatedly conducted, and upper spiral core unit cells are obtained. The end points of every two double spiral core unit cells are collinearly buckled in the direction perpendicular to a panel, and double spiral core single bodies are obtained. The double spiral core single bodies are densely arranged on the panel and then are welded to an upper metal panel and a lower metal panel correspondingly, and a double spiral beam structure core laminboard is obtained. According to the laminboard and the laminboard preparing method, the characteristic that a lattice structure is high in porosity and thecharacteristics that a beam structure is high in bearing capability, good in tenacity and good in damping and energy absorbing effect are combined, the structure strength is greatly improved, the preparing method is simple, cost is low, and wide application prospects are achieved in the fields of safety protection, military, civil damping and energy absorbing and the like.