In deep-sea mining operations, the presence of sediment has a significant impact on hydraulic extraction performance. However, existing studies generally assume a rigid substrate, failing to reflect the effects of real sedimentary environments. To evaluate the adaptability of different hydraulic extraction technologies under sediment-laden boundary conditions, this study coupled VOF interface tracking, discrete element particle dynamics, and a non-Newtonian rheological model to establish a jet-particle-sediment multiphase numerical method. It systematically compared the extraction performance of three mainstream extraction heads: suction-lift, wall-following jet, and jet-flushing. The results indicate that sediment significantly inhibits extraction efficiency. Among the methods, the suction-lift method is most severely affected. The wall-following jet method causes the least disturbance to the environment. However, its extraction capacity is limited. The jet-flushing method is least affected by sediment. It also exhibits the best overall performance. Furthermore, particle dynamics analysis reveals two typical modes of collection failure: escape and retention. Escape failure stems from a lack of lift, causing particles to escape the collection zone without being effectively retained; retention failure results from a spatial lag in the onset of lift, where particles acquire lift but have already missed the optimal lifting position. This study clarifies the significance of sediment in the analysis of hydraulic mineral collection for deep-sea mining and reveals the mechanical mechanisms underlying particle collection failure, thereby providing a theoretical basis for the selection and optimized design of deep-sea mining equipment.