The present disclosure provides a method for manufacturing a low loss ferrule assembly having prefabricated optical fibers, a low loss ferrule assembly having prefabricated optical fibers manufactured according to the method and an optical fiber fixing mold for manufacturing the ferrule assembly, wherein a method for manufacturing a high-precision ferrule assembly comprises: disposing both ends of a plurality of optical fibers within a plurality of grooves at both ends of an optical fiber fixing mold, such that the plurality of optical fibers maintain a specific distance therebetween; disposing the plurality of optical fibers within a housing, and causing the plurality of optical fibers to be fixed relative to the housing, wherein the housing is of a split type; cutting and polishing the optical fibers at a first side of the housing. The solution provided by the present disclosure implements the ferrule assembly of the high-precision optical fiber connector with low costs. The method is simple and effective and has great use value.