Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising alternative to conventional petroleum-based plastics, owing to its considerable biodegradability and physicochemical properties. However, the high raw material costs limit its large-scale production. This study established a novel integrated process by coupling the anaerobic fermentation of vegetable wastes (VW) and pig manure (PM) with PHBV biosynthesis. The results demonstrated appreciable PHBV yields of 0.326 and 0.261 gPHBV/gVFA for VW and PM, respectively. Considering the magnitude of VM and PM in China, this novel approach could result in CO2 emission reduction by up to 12.70 million tons per year, as indicated by environmental impact assessment. Additionally, a preliminary economic analysis suggested economic benefits of up to 9.81 billion USD per year. These findings demonstrate that this integrated process can play a significant role in enabling large-scale production of PHBV while simultaneously resolving environmental pollution related problems associated with conventional plastics.