Abstract: The application of elastic damping material is important for improving the sound insulation performance of building slabs. The optimal selection of elastic damping layer and floating slab mass layer is the key technical measure. In this paper, taking foam rubber damping pad and polyurethane foam board as objects, an experimental study on the performance parameters of these elastic materials is conducted, including measuring the thickness under different load modes, dynamic stiffness, resonance frequency and the damping ratio. And, the influence of changing performance parameters of the elastic material on the floor sound insulation performance is further analyzed. Then, the reinforced concrete residential Type 2 floor is taken as example and the foam rubber damping pad and polyurethane foam board is selected as elastic damping material to cast and mold a floating building sound insulation floor structure for testing the sound insulation performance and its change rule. The results provide an experimental and technical support for the application of elastic material in the floating floor for sound insulation and noise reduction.