Laser driven fusion requires a high degree of uniformity in laser energy deposition in order to achieve the high density compression required for sustaining a thermonuclear burn. While, filamentation severely affects laser irradiation uniformity, which often encountered in indirect-drive research. Therefore, a proper smoothing method must be adopted. With smoothing by spectral dispersion (SSD), the size of focal spot increases greatly for the introduction of phase plate, and pinhole closure will likely happen when the light injected into the hohlraum. To solve this problem, angular spectral dispersion of stacked chirped pulse is proposed here to decrease the target nonuniformity of scale 10 μm to 100 μm. By analyzing the propagating characteristics of frequency-modulated light, mathematical representations are deduced. Simulation indicates, compared with one-dimensional SSD [without random phase plate (RPP)], chirped pulse stacking is more effective in diminishing high frequency modulations on target plane, and the size of smoothed area is dependent on the bandwidth of the stacked pulse in the dispersing direction. These advantages make the technique a promise in promising method laser irradiation uniformity.