The invention belongs to the field of functional polymer materials, and particularly relates to a foaming silicone rubber compound, a low-density silicone rubber sponge and a preparing method of the low-density silicone rubber sponge. The purpose is to provide the new foaming silicone rubber compound. The foaming silicone rubber compound is prepared from a base rubber component A and a base rubber component B, the base rubber component A is prepared from, by weight, 100 parts of component (a), 1-10 parts of component (b), 0.1-10 parts of component (d) and 1-40 parts of component (f) in a mixed mode, and the base rubber component B is prepared from, by weight, 4-20 parts of component (c) and 1-200 ppm of component (e) in a mixed mode. The base rubber component A and the base rubber component B are prepared into the low-density silicone rubber sponge material through foaming sulfuration, and the low-density silicone rubber sponge material has the advantages that the density is low, and pores are fine, smooth and uniform.