Objective To dynamically observe the characteristics of contrast-enhanced ultrasound (CEUS) of rat skeletal muscle at different stages of injury and repair, and to analyze the correlation between them and microvascular density. Methods Forty-eight male SD rats were randomly divided into 8 groups, including 6 rats in normal control group and 42 in injured groups (groups of 1 h, 12 h, 24 h, 48 h, 7 d, 14 d and 28 d after injury). A one-time free fall of an 800 g self-made gravity hammer struck the muscle belly of the right rectus femoris of the rats in the injured groups, thus establishing a model of blunt contusion of the skeletal muscle of the lower limb. At 1 h, 12 h, 24 h, 48 h, 7 d, 14 d and 28 d after the injury, CEUS was performed on the injured sites of skeletal muscle of rats in the injured groups and the corresponding sites in the normal control group. The changes of CEUS characteristics were quantitatively analyzed by computer, and the mean gray scale value of echo intensity (Mean) was obtained. After ultrasound examination, the rats in the injured groups were sacrificed to collect the muscle tissue for hematoxylin-eosin staining, and the microvessel average optical density (MVD) was calculated. Pearson correlation analysis was used to analyze the correlation between MVD and Mean in skeletal muscle injury area. Results The contrast agent signals of skeletal muscle in the injured area of rats in the 1 h group and 12 h group were weak, and most of them showed filling defects. In the 24 h group, the contrast agent in the injured area showed star-shaped distribution, which was low enhancement. In the 48 h group, the contrast agent in the injured area showed patchy distribution, which was slightly enhanced. In the 7 d group, the contrast agent signal in the injured area increased intensively, showing obvious enhancement. In the 14 d group, the contrast agent signal in the injured area was slightly enhanced and was lower than that in the 7 d group. In the 28 d group, the signal of contrast agent in the injured area was similar to that in the normal control group, showing low enhancement. Compared with the normal control group, the Mean of the injured area were significantly decreased in the 1 h, 12 h and 24 h groups (all P＜0.05), the Mean of the injured area was increased in the 48 h group without a significant difference (P＞0.05), and the Mean of the injured area was further increased to the peak in the 7 d group and was still higher in the 14 d group with significant differences (both P＜0.05). The Mean of the injured area in the 28 d group was similar to that in the normal control group (P＞0.05). Compared with the 1 h group, the MVD of the 12 h group was not significantly changed (P＞0.05). The MVD of the 24 h to 28 d groups was all significantly increased (all P＜0.05), with the highest in the 7 d group. The Mean was positively correlated with the MVD in the injury area of rats (r＝0.840, P＜0.001). Conclusion CEUS can dynamically observe the microcirculation perfusion of injured skeletal muscle in different periods, and computer-aided image analysis can quantitatively describe the change of the signal intensity of contrast agent, which has good correlation with the distribution of microvessels in the muscle.