This study reports on the development of a sound-absorbing/thermal-insulating nonwoven composite board and its relevant manufacturing process. The developed nonwoven composite board is used to reduce airborne noise and achieve thermal insulation through its irregular, three-dimensional porous structure. The nonwoven composite board is made of recycled polypropylene nonwoven selvages, two types of polyester fiber, and thermoplastic polyurethane. The experimental results reveal the excellent thermal insulating properties of both the polyester fiber/polypropylene and polyester fiber/polypropylene/thermoplastic polyurethane composite boards. In addition, the sound absorption of the polyester fiber/polypropylene /thermoplastic polyurethane composite board performs well in low and medium frequency ranges. For frequencies below 1000 Hz, the best sound absorption coefficient of polyester fiber/polypropylene/thermoplastic polyurethane composite board can reach a value of up to 0.698.