Abstract: In order to obtain high performance silicone foam material to meeting the requirements for engineering projects,the experimental investigation of scanning electron microscope experiment and uniaxial compression and stress relaxation test were conducted on silicone foam prepared by mixed foaming method and dissolve-separating foaming method. And the comprehensive performance of two kinds of silicone foams was evaluated roundly by comparing and analyzing of microstructure features and mechanical performance. The result showed that mechanical properties of the material are mainly affected by cellular structure. Spherical cellular silicone foam prepared by dissolve-separating foaming method has better compression properties and lower relaxation rate than mixed cellular silicone foam prepared by mixed foaming method,and the repeatability of experimental data is rather good. Mechanical performance can be further improved by using synthesis technology of random copolymer and multi-block copolymer.