Precise physical experiments place strict requirements on target illumination uniformity in inertial confinement fusion research. Currently, the main stream of beam smoothing technology adopted in solid-state laser driver combines smoothing by spectral dispersion （SSD）, phase plate and beam overlapping. A new smoothing method aimed at indirect-drive laser fusion is studied here, which uses linearly modulated light and angular spectral dispersion. After using this technique, high frequency modulations on the far field could be smoothed. In the meantime, near field after the dispersion grating could be smoothed too. Experimental results show that the measured spectrum is similar to the simulated one. Phase modulator is not necessary in this method, while it is a crucial element in traditional SSD method.