We generate a type of pseudo-thermal light field via sparse structured illumination source. Genetic algorithm is utilized to optimize the source's spatial configuration and the property of pseudo-thermal light field is improved. Both simulated and experimental results demonstrate that the periodic distribution of normalized second-order intensity correlation function is effectively suppressed by optimizing the spatial configuration of sparse structured illumination source and the quality of ghost imaging can be obviously increased. This optimized sparse structured illumination source may be applied to the applications like remote sensing with moving targets.