In order to study the influence of different compaction methods on the micro-structural characteristics and compressive strength of SMA-13 asphalt mixture, Marshall compaction instrument and rotary compaction instrument were used in the laboratory to make SMA-13 asphalt mixture specimens with different air voids. CT scanning and image processing were used to extract and compare the changes in parameters such as voids ratio, the number of voids, average equivalent diameter of voids, and void contour fractal dimension of various types of specimens. The compressive strength of various types of SMA-13 asphalt mixture specimens was obtained by uniaxial compression test and triaxial compression test. The results show that the variability of voids ratio, the number of voids, average equivalent diameter of voids, and void contour fractal dimension along the layer of SMA-13 specimens formed by rotary compaction is greater than that of specimens formed by Marshall compaction. The mean value of the number of voids and the mean value of average equivalent diameter of voids of the specimens formed by Marshall compaction are larger than those of the specimens formed by rotary compaction. The uniaxial compressive strength and triaxial compressive strength of SMA-13 asphalt mixture under two compaction methods decrease with with the increase of the mean value of the number of voids, the mean value of average equivalent diameter of voids and the mean value of void contour fractal dimension.