The dynamic balance equation of tunnel structure under an explosion loading action is established based on the theory of cylindrical thin shell structure. An integral equation in the Fourier transformed filed that represents the displacement field in tunnel under the explosion loading is deduced by using the integral transformation. Taking an engineering project as example, the time-history curves of displacement and maximum circular normal stress in explosion center are given by using the inverse fast Fourier transform （IFFT）. Furthermore, the variation curves of displacement and the maximum normal stress at a certain time in x direction are given also. The results show good agreement with the numerical computation results. This mean feasibility of the model and the method.