The invention belongs to the field of silencing materials, and particularly relates to a novel sound-absorbing felt. The sound-absorbing felt provided by the invention uses preoxidized polyacrylonitrile fiber as a sound-absorbing material for the first time, so as to obtain the novel sound-absorbing felt; not only the sound-absorbing felt has better acoustic performance than that of a glass wool product, but also the fiber is flexible and free of breakage, an environment pollution problem is avoided, and the sound-absorbing felt is friendly to the health of an operator; in addition, the sound-absorbing felt provided by the invention has good fire resistance and flame retardance, has an oxygen index of 50 or above, and is significantly better than other organic fibers. The preoxidized polyacrylonitrile fiber (shortened as preoxidized fiber) used by the sound-absorbing felt is an intermediate product in carbon fiber production. High-performance carbon fiber has an extremely high performance requirement on the preoxidized polyacrylonitrile fiber, a large amount of waste fiber is produced in the production process, and the waste fiber is used as a raw material for fiber sound-absorbingfelt production, so that the production cost is effectively reduced; a sound-absorbing layer produced from the preoxidized polyacrylonitrile fiber can play a very good sound-absorbing effect on a low-frequency sound source and meets a special noise-reducing need of a substation.