As global mining is transforming towards green and sustainable development, open-pit mines are generally confronted with a severe challenge that existing tailings storage facilities encroach on the stope boundary during slope expansion and deepening. To address the problem of "tailings encroachment", a new integrated model for full-cycle tailings management featuring "hydraulic-mechanical collaboration and multi-objective optimization of resources, space and safety" was proposed based on a tailings management project of a copper-cobalt mine in Africa. A theoretical framework integrating "objective coordination, technical coordination and management coordination" was established by this model. Its core lies in adopting the spatiotemporal coupling technology of hydraulic mining with large cutter suction dredgers and mechanical excavation, so as to realize efficient recovery of tailings resources and safe release of stope space simultaneously. An integrated "space-air-ground" monitoring network was deployed in the project, and a proactive control strategy of "phased water impoundment and dynamic early warning" was innovatively adopted. The safety of operations adjacent to the high and steep stope slope is guaranteed by these measures. During construction, the maximum horizontal displacement of the north-side seepage cut-off dam is maintained at 67.4 mm. Practice shows that approximately 8 320 kt of tailings are treated and over 4.2×10⁶ m³ of stope space are released by this model. Distinct economic, safety and environmental benefits are achieved, and a replicable and systematic technical solution is provided for this common problem in the mining industry.