<p>Under the ultrafast heat conduction conditions (e.g., underground explosions and laser breaking rock), the conventional heat conduction models exhibit clear limitations in capturing the hydro-thermo-mechanical behavior in the saturated porous medium. Nevertheless, the current constitutive models and dynamic response predictions on this topic neglect the phase lag of temperature gradients and memory-dependent effects in the heat carrier evolution. To overcome such limitations, this paper aims to develop a coupled poro-visco-thermoelastic model based on the new non-singular fractional dual-phase-lag heat conduction law with Atangana–Baleanu (AB) and tempered Caputo (TC) fractional derivatives to characterize the temporal nonlocal memory dependency and the finite speed of heat transport. The proposed model is applied to investigate the transient hydro-thermo-visco-mechanical coupling responses of an unlined circular tunnel under thermal shock loading. A semi-analytical solution is obtained using Laplace transformation and a fast Fourier-based numerical inversion. Dimensionless results reveal that the fractional parameters in the new established model are capable of capturing the memory effects and finite-speed heat transport, enabling effective modulation of temperature dissipation, pore pressure evolution, and stress responses. The achieved results in this work are supporting the thermal/mechanical control and safety evaluation of saturated tunnels in the ultrafast heating condition.</p>