The addition-type liquid silicone rubber was foamed using physical foaming agents, sodium bicarbonate as a foaming aid, and hollow glass microspheres, respectively, to obtain foamed silicone rubber. This paper deeply investigated the effects of three foaming aids and their different dosages on the foaming effect, and conducted characterization and testing of the structure and properties of the successfully prepared foamed silicone rubber. The research results showed that the foaming effect of the foamed silicone rubber prepared using physical foaming agents was more ideal, and medium-foaming foam materials could be prepared; the tensile strength and elongation increased with the increase in the density of the foamed silicone rubber; the pressure during molding has a significant impact on the foaming effect, and the foaming ratio increased as the pressure decreased.