Spatial intensity modulation in amplified laser beams, particularly hot spots, critically constrains attainable pulse peak power due to the damage threshold limitations of four-grating compressors. This study demonstrates that double-smoothing grating compressor (DSGC) configuration effectively suppress modulation through directional beam smoothing. Our systematic investigation validated the double-smoothing effect through numerical simulations and experimental measurements, with comprehensive spatiotemporal analysis revealing excellent agreement between numerical and practical pulse characteristics. Crucially, DSGC enables 1.74 times energy output boost compared to conventional compressors. These findings establish DSGC as a pivotal advancement for next-generation ultrahigh-power laser systems, providing a viable pathway toward 100s PW output through optimized spatial energy redistribution.