A scheme of combining smoothing by spectral dispersion (SSD) technology with lens array (LA) is introduced in laser produced shock wave experiments. The feasibility of the scheme is analyzed by numerical simulation. It is shown that the beam uniformity in near field could be improved by the phase modulation and spectral dispersion, and a smoothed pattern with flat-top and sharp-edge profile could be obtained in the focal plane. The irradiation nonuniformity of the focal pattern depends on the design of both SSD and LA but less on the incident beam in comparison with other smoothing methods. Experiments are conducted by adopting the schemes of LA and SSD, distributed phase plate (DPP) and SSD. The results are beneficial for better smoothing in laser-plasma interaction experiments in the future.