The sound insulation performance of nuclear power related equipment and pipelines is of great practical significance for the safe operation of nuclear power equipment. At the same time, the surface of the equipment is often covered with an insulating layer to maintain the temperature of the nuclear power equipment. If the thermal insulation material can play the role of vibration isolation and noise reduction, it will undoubtedly have a positive effect on the vibration and noise control of nuclear power equipment. Aiming at the insulation layer structure using glass wool as insulation material, this paper studies the acoustic performance of the pipeline after installing the insulation layer by means of experiments and theoretical calculations. This paper verifies that the thermal insulation layer structure can effectively improve the insertion loss and sound transmission loss of the structure while meeting the requirements of the thermal insulation layer. At the same time, this paper conducts a parametric analysis study to study the effect of different structural variables on the sound insulation performance of the thermal insulation layer. The results show that the increase in the bulk density of glass wool, the increase in the thickness of the metal coat, and the additional damping layer all increase the insertion loss of the structure.