Terahertz signal-based object surface detection method and system

The invention discloses an object surface detection method and system based on a terahertz signal, and the method comprises the following steps: collecting the terahertz signal with sample information, and obtaining a near-field intensity picture of a sample surface based on the terahertz signal; dividing the near-field intensity picture into one or more sub-regions based on near-field intensity distribution in the near-field intensity picture; and obtaining frequency domain signals of one or more points in the sub-regions, and obtaining materials of the sub-regions based on the frequency domain signals of the sub-regions. The near-field intensity distribution of the surface of the sample is quickly obtained based on the time domain information of the terahertz signal to confirm the sub-region range, and then the material information of each sub-region is confirmed based on the frequency domain information of the terahertz signal, so that the distribution condition of each material layer on the surface of an