The invention provides a method for building a sound-recording studio and an anechoic chamber with flexible structures, and aims to provide a flexible structural sound-recording studio and a flexible structural anechoic chamber which adopt rigid structures as support bodies and adopt hollow sandwiched flexible structural wall surfaces as room frameworks. The adopted materials are universal and cheap, the sound-recording studio and the anechoic chamber are provided with a rubber airbag door capable of inflating and deflating and a three-layer hollow synthetic material plate sound isolation monitoring window which are arranged at the position of a middle partition wall, the lower part of the middle partition wall is provided with a vertical cable transmission hole and a circulating hole, the side, close to the recording room, of the monitoring window is a convex cambered surface, the background noise is lower than 8dB(A), and the cut-off frequency range can be adjusted to be 125 to 50Hz. Because of a vault type roof and a suspended flexible floor, the construction is convenient and quick, and standardized production can be realized. The interference is inhibited, the reflection and resonance are reduced, the sound isolation and attenuation are realized, the purity of the sound is improved so that the sound tends to be perfect, and the method can be widely applied to the construction of movie theaters, anechoic chambers, direct broadcasting rooms, sound-recording studios and the like.