Abstract: To investigate the blast-resistance performance of shield tunnels subjected to internal explosive loads, a field blast test was conducted on a scaled shield tunnel model. The damage patterns and dynamic responses under internal explosion loads were analyzed and compared with the results of similar experimental studies reported in the literature. The results show that the dynamic response of the segmental lining under internal explosions is significantly influenced by structural configuration and overburden conditions. Under central explosion scenarios, the vibration response at the vault is much stronger than that at the springline. Under close-in blast loads, damage in the near-field region mainly includes segmental joint dislocation, concrete spalling at circumferential joints, and concrete crushing at longitudinal joints; while in the far-field region, circumferential and longitudinal joint dislocation and tensile cracking of concrete are dominant. Under contact explosion loads, local blast craters and radial cracking are the main failure modes, and the presence or absence of segmental joints has a significant effect on the crater size and shape. Comparative analysis with published internal blast test results on shield tunnels indicates that the failure mode is strongly correlated with the blast charge weight: with increasing charge weight, the dominant failure mode shifts from tensile cracking along longitudinal joints to shear failure along circumferential joints, and further increase in charge weight may trigger a risk of collapse.