With increasing control of external phosphorus input, internal sediment phosphorus release from sediment is critical for mitigating water eutrophication. This study, for the first time, proposes a strategy integrating phosphorus release promotion and subsequent immobilization in sediment. Three experimental groups were established: blank control, temperature-controlled, and temperature controlled coupled electroosmosis adsorption. Changes in phosphorus content in overlying water, sediment pore water, and sediment were analyzed to evaluate the technology’s efficacy. Results showed that: (1) Temperature control at 30 °C increased sediment phosphorus release by 24.1% after 7 d; (2) The coupled technology simultaneously reduced sediment phosphorus content and inhibited its release via accelerating phosphorus release and in-situ removal. Specifically, sediment total phosphorus (TP) decreased by ~30%, labile phosphorus fractions (NH₄Cl–P, Fe–P, Al–P) declined by 51.2%, while stable fractions (Ca–P, Res–P) increased by 28.7%. The phosphorus release flux at the sediment–water interface decreased by 73.2%, overlying water TP dropped from 0.6 to 0.4 mg/L, and with stability maintained in summer and autumn. These findings demonstrate the technology’s potential for long-term control of internal sediment phosphorus, providing an effective approach for eutrophication management.