<p>This paper synthesizes multi-element metal sulfide anode materials for sodium-ion batteries through rational experimental design, component control, and composite modification to enhance cycle life and electrochemical performance. An orthogonal experiment is designed to systematically investigate and optimize the solvothermal synthesis conditions for multi-component ZnCoNi sulfide composites. The electrochemical sodium storage performance of the optimized material is further improved by constructing heterogeneous nanostructures and carbon composite. Results show that after carbon composite, the charge specific capacity increases from 492.6 mAh·g⁻¹ to 528.4 mAh·g⁻¹ at 0.1 A·g⁻¹ after 50 cycles, with an 87.3% capacity retention rate compared to the first cycle. Moreover, the material maintains a capacity of 437.7 mAh·g⁻¹ after 500 cycles at 1.0 A·g⁻¹, demonstrating enhanced cycling stability. The synergistic interactions at the heterostructure interfaces also significantly boost the overall electrochemical performance of the battery.</p>