This study explores the impact of multi-chart layout design of Large-Screen Interface, particularly considering multi-chart arrangement, the number of charts, and chart border style, on cognitive performance and visual search efficiency in large-screen interface design. Adopting a 3 × 3 × 5 within-subject design, participants completed visual search tasks on a large display under varying interface conditions. The results revealed that different multi-chart layout significantly influenced reaction times, indicating heightened cognitive load. Results show that increasing chart numbers (6 to 10) raises cognitive load, while left or right-side arrangement, where multiple charts are grouped on one side, improve efficiency compared to distributed arrangement. Chart border style also influenced performance, with clear dividers and minimal distractions enhancing information saliency and reducing visual interference. Furthermore, interactions between multi-chart arrangement, number of charts, and chart border style further emphasized their combined effects on user performance. These findings underscore the necessity of optimizing multi-chart layout designs to improve usability and decision-making efficiency in large-screen interfaces. Additionally, the study highlights the lack of a unified design standard for multi-chart arrangement, necessitating further research to establish systematic guidelines.