This study investigates the effects of digital interface structure on the operational performance of unmanned and manned–unmanned integrated mechanical systems from a human factors perspective. Using case-based comparative analysis, changes in response time, operation error rate, and situational awareness accuracy before and after interface redesign were examined. The results indicate that improvements in interface integration, procedural simplification, and consistency significantly enhance operational performance without modifying mechanical hardware or control algorithms. The study highlights the importance of incorporating human factors engineering into the early design and evaluation stages of complex mechanical systems.