The polyester sound-absorbing board is made by high-tech hot pressing of fiber strands with a diameter of only 13 threads. It naturally forms a porous structure, which can replace harmful traditional sound-absorbing boards such as sponge, glass wool, and rock wool. It is a new type of environmentally friendly sound-absorbing material that can come into direct contact with the human body without harming it, and does not release pollutants or fine fibers. With permanent flame-retardant technology, it is more advanced compared to the conventional flame-retardant process using soaking agents.