For the quantitative evaluation configuration of coarse aggregate of asphalt mixture in the process of forming, this paper proposes a synthesis of the center of mass distance using digital image processing technology. Images captured by SGC forming AC-20 specimens under different compaction number. The parameter was extracted from three images of each specimen. Two-dimensional accumulative sieve residue and single sieve residue coarse aggregate are calculated respectively to obtain synthesis distance. Results indicate that while gyratory compaction may not improve the uniformity of the coarse aggregate, larger coarse aggregate configurations improve considerably.