The invention discloses a central refrigeration machine room modular prefabrication and assembled construction method. The method comprises: refrigeration machine room standard family storehouse establishment, digital module design, three-dimensional precision control, factory full-automation prefabrication and assembled construction. A standard family storehouse is a central refrigeration machine room complete device, valve and component family storehouse created based on the size of an entity. A digital module is generated after a high-precision BIM model is subjected to scientific segmented encoding. The three-dimensional precision control comprises: rechecking and measuring a central refrigeration machine room building structure, constructing an absolute coordinate system, and ensuring that the model design precision, the processing precision and the field assembly precision are controlled uniformly and reliably. The factory full-automation prefabrication comprises factory production performed according to a digital module processing diagram. The assembled construction comprises segmented flange connection, and integrated lifting and mounting. The central refrigeration machine room modular prefabrication and assembled construction method has the advantages that mounting efficiency of a central refrigeration machine room can be improved, mounting quality and precision are improved, the reproduction and transplantation performances of a standard module design are high, and industrial production conditions are met.