Abstract: To reduce the impact of noise generated by ancillary buildings on living condition and improve the acoustic environment of residential buildings, the noise source and the noise propagation routes of the underground heat exchange station of the existing residential building are studied in this paper. Based on the measured data of indoor noise in the underground heat exchange station of existing residential buildings, the acoustic characteristics of indoor environment are analyzed. From the comprehensive consideration of the health and comfort of residents, the noise reduction processing and transformation design scheme for the auxiliary building is proposed. The spatial noise after the transformation is significantly reduced, and the acoustic environment index of the living space after transformation meets the standard requirements, so that the acoustic environment of the residential building is effectively improved. The transformation design scheme proposed in this paper provides a technical support for the development of acoustic design standards for ancillary buildings in civil construction.