The invention relates to the field of insulation board manufacturing, in particular to an additive formula for improving the performance of an insulation board, which comprises P.O525R ordinary Portland cement, graphite powder, glass beads, an organic silicon water repellent, a cement composite early strength agent, silica fume, water, ethylene-vinyl acetate copolymer emulsion, a polyether defoaming agent and a sodium gluconate retarder. The production method for improving the performance of the insulation board comprises the following steps: step 1, pretreating polystyrene foam particles by using phenolic aldehyde epoxy resin; step 2, preparing equipment; step 3, coating an inorganic cementing material on a substrate; and step 4, making the inorganic cementing material permeate the substrate. When the technical scheme is adopted, the strength index of the insulation board can be improved.