Waste activated sludge (WAS) is a valuable waste resource rich in organic matter andnutrients, presenting significant potential for recycling. The recovery of carbon (C) and phosphorus (P)from WAS contributes to achieving carbon neutrality goals and helps alleviate the global shortage ofphosphorus resources, thereby promoting sustainable agriculture. This study aimed to assess the effectEnergy Environmental Protectionof potassium ferrate (PF) on the co-fermentation system of waste activated sludge (WAS) and cornstraw (CS) under alkaline conditions. Laboratory-scale sequencing batch reactors were used toinvestigate the impact of various PF dosages (0, 0.05, 0.20, 0.50 g/g VSS) on the enhancedsolubilization, hydrolysis, and formation of short-chain fatty acids (SCFAs) in the co-fermentationsystem. The results demonstrated that PF pretreatment effectively disrupted the structure of WAS flocsand CS, facilitating the release of organic matter from WAS cells and extracellular polymericsubstances (EPS), and promoting the release of polysaccharides from CS. This effect was morepronounced at higher PF dosages (≥0.20 g/g VSS). After a 24-hour pretreatment, the levels ofsoluble chemical oxygen demand (SCOD), soluble polysaccharides, and proteins in the 0.50 g/g VSSPF dosage group increased by 11.9, 9.41, and 4.75 times, respectively, compared to the non-dosagegroup. The maximum accumulation of SCFAs at various PF dosages (0, 0.05, 0.20, 0.50 g/g VSS)increased by 1.47, 1.92, and 2.21 times, respectively, compared to the non-dosage group, and theproportion of acetic acid, which is easily utilized by microorganisms, also increased. Microbialcommunity analysis revealed a reduction in the Shannon index, with a notable enrichment offermentation-related functional bacteria, including Firmicutes and Bacteroidota. Additionally, PFaddition significantly enhanced the bioavailability of CS. At the genus level, acid-producingfermentative bacteria such as Macellibacteroides, Bacteroides, and Clostridium, known for utilizingpolysaccharides like cellulose and hemicellulose, dominated the system, further boosting SCFAsproduction. Clostridium, an iron-reducing bacterium, can be selectively enriched at high concentrationsof Fe(Ⅲ), further enhancing its abundance. The fermentation supernatant from PF-treated sludge had ahigher SCFAs content and lower phosphorus (P) content, making it a suitable carbon source supplementfor wastewater treatment plants. Additionally, the formation of vivianite was observed in theexperimental groups, facilitating P recovery. When PF was added at 0.20 g/g VSS, the recoverypotential of SCFAs and P was optimal, and the economic benefit was the highest, reaching 63.96CNY/m WAS. Therefore, a PF dosage of 0.20 g/g VSS is recommended, providing a valuablereference for the resource recovery and utilization of WAS and CS. This method demonstratessignificant engineering application potential and economic benefits, offering a novel approach for wasteresource utilization.