The invention discloses a preparation method of two-component sound-absorbing cotton. The two-component sound-absorbing cotton comprises a cotton core, a seal edge, a through hole, a semicircular slotand a curved slot. The cotton core comprises an external layer, an intermediate layer, a core layer, V-shaped connection holes and tree-shaped connection holes. The central main part of the two-component sound-absorbing cotton is designed as the cotton core, the periphery of which is designed as the seal edge. The bottom right corner of the cotton core is provided with the through hole, the periphery of which is provided with the seal edge. The bottom left corner of the two-component sound-absorbing cotton is designed as the curved slot. The central bottom edge of the right side of the two-component sound-absorbing cotton is designed as the semicircular slot. Through reasonable raw material selection and reasonable ratio of raw materials, the prepared two-component sound-absorbing cottonis light in weight, has good sound-absorbing effect and performance, has strong decorative performance, is convenient for processing, raises work efficiency of processing, reduces pollution due to useof green materials, raises environmental protection effect, and is convenient for recycling of sound-absorbing cotton.