The invention discloses a factory prefabrication construction method for pipelines. The method comprises the following steps that 1, a three-dimension preassembly model of the pipelines is built; 2, the pipeline prefabrication degree is determined, drawing optimization is completed with a computer, pipeline and pipe fitting manufacturing units are determined, and a machining drawing is drawn out; 3, a pipeline factory assembly line machining process is made according to the machining drawing, and then according to the determined machining process, a prefabrication site is planned, and prefabrication devices are arranged; 4, a pipeline machining prefabrication factory is selected; 5, the prefabrication factory carries out factory machining prefabrication on the pipelines according to the machining drawing, and 6, the prefabricated pipelines and pipe fittings are transported to a construction site for installation, specifically, the prefabrication devices comprise the lifting pipeline prefabrication bracket. According to the factory prefabrication construction method for the pipelines, machining prefabrication is not affected by weather and conditions of the construction site, and through the factory production mode, the manufacturing cost is lowered, the construction efficiency can be improved, labor allocation on the site is relieved, and construction quality and safety of constructors can be guaranteed.