SLM was systematically employed to fabricate Fe-based MGs. The focus was on how laser power can be optimized to influence forming quality. Scanning speed can also be optimized to influence forming quality. In addition, remelting strategies can be optimized to influence forming quality. A robust processing window was identified, enabling the production of centimeter-scale, fully amorphous bulk samples with high density and no crystallization. The remelting process was demonstrated to enhance surface quality, mechanical properties, and densification while preserving the amorphous structure. Furthermore, a biomimetic multi-level structure can be directly constructed on the alloy surface in a single-step AM process without chemical modification, achieving stable superhydrophobicity. Based on this functional surface, a dual-mode mechanical energy harvesting system was developed using an Fe-based MGs/PTFE composite structure. By leveraging droplet impact and sliding friction, the system efficiently converts ambient mechanical energy into electricity. This capability makes it a promising candidate for integration into self-powered systems responsive to various mechanical stimuli. This approach breaks the size limitations of Fe-based MGs and enables integrated structure–function manufacturing, offering new solutions for applications in aerospace, precision engineering, and related fields.