Efficient resource recovery is crucial for sustaining food production and alleviating stress on ecosystems. This study combines hydrothermal pretreatment with polyvinylidene fluoride (PVDF)-hydrochar nanocomposite membranes for near-complete resource recovery in kitchen waste treatment. The dual-functionalized pretreatment, which combines targeted conversion/enrichment with adsorption/filtration, effectively addresses the limitations of existing membrane separation technologies, including low nutrient recovery selectivity, low flux, and high costs. Within a wide pH range (3-11), the optimized lanthanum-doped hydrochar demonstrated over 99% phosphorus recovery, alongside exceptional nutrient recovery potential (over 289.71 mg P/g). The innovative composite membrane design successfully processed over 1,000 bed volumes of biogas slurry containing high phosphorus levels across three in-situ rejuvenation cycles, achieving nearly a 30-fold increase in membrane utilization compared to pristine PVDF membranes (36 bed volumes). The durability and fouling resistance of the composite membranes were enhanced through a synergistic mechanism that included ligand exchange and retention, as well as improved membrane surface properties. This facilitated the selective and efficient recovery of nutrients (99.33% P and 50.81% N) and enabled a profitable turnaround for anaerobic by-product upcycling ( 8.51/ton). This study offers novel solutions to address the phosphorus scarcity crisis and promotes the integration of organic waste management with low carbon value addition.