An Insulated Concrete Sandwich Panel (ICSP) consists of two exterior concrete layers and a middle functional layer, which are connected by shear connectors. It has been increasingly used as building roof and wall panels due to its multifunctional load bearing and energy-efficient capacities. Existing research is mainly focused on its mechanical and energy performances [1-2]. This study forms an important step to evaluate its noise reduction effect based on a combined analytical, experimental and Finite Element (FE) study as follows: (1) An acoustic analytical model was constructed using the periodic structure theory, where the connectors were simplified by a "mass spring" model. (2) An ICSP with dimensions of 1600 mm×1600 mm×150 mm (length×width×thickness), which had a 20 mm thick polyurethane middle layer and four Fiber-Reinforced Polymer (FRP) pipe connectors, was fabricated. An air sound insulation experiment was conducted in an acoustic lab. (3) A three-dimensional FE model on the ICSP was constructed using ANSYS, with four sides simply supported. The results show that the sound insulation frequency characteristic curves from the three results are relatively consistent. The weighted sound insulation Rw (C; Ctrl) are 49 (-1; -4) dB, 49 (-1; -4) dB, and 52 (-2; -5), from the analytical, experimental, and FE results, respectively. Therefore, there is a good correlation among the three results, proving the accuracy of the analytical model. Once proven accurate, the analytical model was further used to evaluate the influence of different parameters, including the axial stiffness of the connectors, the thickness of different layers, and the Young's modulus of the middle functional material. It can be concluded that ICSP has good acoustic insulation performance, which can be designed to meet the national code requirements [3]. This study can be used to optimize the design and promote the applications of ICSPs.