Abstract: In the transmission and reflection imaging modes, we realize the key algorithms and techniques of 2D imaging of objects.According to time-domain Terahertz signals collected by THz imaging instrument, we use MATLAB programming to realize key algorithm for 2D imaging to accomplish the improvement and expansion added to the original function.In the complex practical applications, imaging experiments are performed on complex samples, and the image is reconstructed by using the tomography technology.Compared with the real,the correctness and practicability of the program are verified.