Abstract: This paper discusses electromagnetic modeling and analysis for pulsed terahertz(THz) testing of hidden corrosion under aircraft coating. A time domain differential equation model is established by using the axisymmetrical form of the Maxwell’s equations, and the finite element time domain(FETD) method is applied to solve the model. In numeric examples, the responses of coated conductors with different defect size to incident THz pulse are obtained, and the variations of responses in space and time are summarized respectively. Results show this method can be used for analysis and prediction of electromagnetic phenomenon during pulsed THz testing. The paper provides some theoretical basis for the development of pulsed THz nondestructive testing technology.