The theory of generalized thermoelastic diffusion of Sherief is used to investigate the dynamic response of infinite elastic medium with a cylindrical tunnel subjected to a time-dependent thermal shock. Without the customary use of potential functions, the direction method of solution, with the help of Laplace technique, is used to solve the coupling thermal, chemical and mechanical governing equation. The analytical solutions of temperature increment, displacement, stress and chemical potential are obtained in the transform domain, and by using the inverse Laplace transform, the numerical results are obtained and used to analyze the distribution of temperature increment, stress, displacement and chemical potential on the condition of thermo-chemo-mechanical coupling.