To achieve a uniform lighting environment suitable for cockpit man-machine training in the target area (4 m×6 m), a design method utilizing area splice of a high-power LED array was proposed. In order to address the issue of uneven illuminance distribution in traditional rectangular and circular arrays, the arrangement was optimized through the employment of an improved array distribution and an enhanced particle swarm optimization algorithm. A luminance uniformity of 91.17% was exhibited by the improved single-module array based on simulation analysis. Due to the influence of installation errors, the actual test light uniformity was measured at 89%. After the optimization of the multi-module LED array through splicing, an illumination uniformity of 85.83% and a light energy utilization of 87.40% were indicated by the simulation results. The improved multi-module array, designed using the area splicing method, is indicated to be more suitable for simulating large area lighting environments. The characteristics of high illuminance uniformity and a high light energy utilization rate are possessed by the multi-module array. These findings hold significant reference value for practical applications.