This paper uses the parameter extraction model of the transmission terahertz time-domain spectroscopy technology to theoretically simulate the terahertz time-domain signal of the sample, and then simulates and analyzes the Fabry-Perot effect. The simulated sample signal is very close to the measured sample signal. Through simulation, the influence of thickness, refractive index， and extinction coefficient on the terahertz time-domain signal is analyzed. Finally, suggestions for sample detection and signal processing of terahertz time-domain spectroscopy are put forward.

Fabry-Perot;optical parameters;spectral analysis;simulation;terahertz