The non-Fourier effects on transient temperature response in semitransparent medium with black boundary surfaces caused by laser pulse are studied. The processes of the coupled conduction and radiation heat transfer in a one-dimensional semitransparent slab with black boundaries are analyzed numerically. The hyperbolic heat conduction equation is solved by the flux-splitting method, and the radiative transfer equation is solved by the discrete ordinate method. The transient temperature response obtained from hyperbolic heat conduction equation is compared with those obtained from the classical parabolic heat conduction equation. The results show that the non-Fourier effect can be important when the conduction-to-radiation parameter and the thermal relaxation time of heat conduction are larger. Under this condition, for the laser-flash measurement of the thermal diffusivity in semitransparent materials, omitting the non-Fourier effect can result in significant errors.