For a fan-wall data center, a large number of fans can be installed on one side of the server room to facilitate the introduction of outdoor cold air into the server room for effective heat dissipation, thereby accomplishing the objective of energy conservation. However, fewer researches are currently available on optimizing the fan array layout of fan-wall data centers to improve the thermal environment. This study aims to explore the impact of fan array layout parameters, including the area, distance, and height of the fan array, on the cooling efficiency of server rooms through both single-factor experiments and orthogonal experiments. The results indicate that: (1) In a fan-wall cooling system, racks closest to the fan wall have high temperature fluctuations and less orderly airflow organization. (2) The optimization of the fan array layout in a data center is primarily influenced by the height, area and distance of the fan array. (3) For a DC, the fan array layout, with an area of 4320 cm2, a distance of 81 cm, and a height of 18 cm, can achieve optimal conditions and effectively enhances the overall thermal performance of the rack. By optimizing the layout of the fan array, a more efficient combination of parameters for air distribution can be achieved, providing a reference for the arrangement and layout of fan arrays in actual engineering applications.