The invention discloses a modular box-type assembly-structure low-noise cabinet. The cabinet comprises a chassis, an electric control cabinet, a host cabinet, a main silencing cabinet and a filteringcabinet, wherein the electric control cabinet, the host cabinet, the main silencing cabinet and the filtering cabinet are sequentially arranged on the chassis from left to right. The host cabinet is of a rectangular structure and comprises a host cabinet body, a main top cabinet and a main bottom cabinet, the main top cabinet and the main bottom cabinet are fixed at the upper end and the lower endof the host cabinet body respectively, and an inner cavity of the host cabinet body correspondingly communicates with an inner cavity of the main top cabinet and an inner cavity of the main bottom cabinet. Sound insulation board units are arranged in the directions of the six side faces of the host cabinet body respectively, and each sound insulation board unit comprises an inner layer sound insulation board and an outer layer sound insulation board. The front and back surfaces of each inner layer sound insulation board are each provided with silencing cotton, and silencing cotton is attachedto the inner side of each outer layer sound insulation board. During assembly, the working space is easy to arrange, the operation is convenient, warping deformation is not likely to happen, the structural strength is good, and the sealing surface can be easily ensured to be flat. Noise of a host needs to penetrate through three layers of sound insulation cotton when spreading in any direction, so that the sound insulation effect is good.