The present invention discloses a processing and manufacturing method for a winding drum variable pitch broken line rope troughs, consisting of a starting point control method, a broken line inflexion consistency keeping method, a variable pitch broken line trough processing method and a broken line rope trough section point track forming method which are required when the winding drum variable pitch broken line rope trough is processed on a large horizontal lathe. The winding drum variable pitch broken line rope trough processed by utilizing the manufacture method has the advantages of meeting design requirement, improving process quality, leading the process and manufacture of the winding drum variable pitch broken line rope trough to come true, providing equipment guarantee for large hydro-junction engineering and mine deep well exploitation and having wide application and popularization value.