Due to the special vehicle′s narrow space, lighting layout is limited and the difficulty is increased. Based on the theoretical analysis of illumination and received optical power, both the direct and the first reflection models of illumination and received optical power were developed. In illumination demand constraint conditions, an optimal scheme of rectangular lighting layout for narrow vehicle space was proposed based on optical power evenly distribution principle. Simulation experiments proved that the optimizing rectangular layout scheme is valid as follows: the average received optical power was obtained about -0.5 dBm and the illumination range was 333.74-466.44 lx in 2 m×2 m×1.5 m space size, uniform illumination rate was 79.5%, which meet the international illumination standards and the actual data communication in a special vehicle.