As the cornerstone of information technology, the semiconductor industry relies on doping the surface of intrinsic semiconductor wafers as one of its core processes to fabricate high-performance optoelectronic devices and integrated circuits. To improve production efficiency and ensure device quality, there is an urgent need to develop a rapid, non-contact, and non-destructive technique for extracting doping layer thickness and doping concentration parameters. This paper proposes a method that utilizes Fabry-Perot resonance spectroscopy to calculate the doping layer thickness and doping concentration of semiconductor wafers. Based on electromagnetic wave scattering matrix theory, this method enables efficient numerical calculations of the terahertz transmission, reflection, and absorption spectra of semiconductor wafers. By constructing a correlation model between doping layer thickness, doping concentration, and Fabry-Perot resonance spectra, it provides a theoretical foundation for fitting experimental spectra and extracting doping parameters with high precision. This method is expected to offer an efficient, non-destructive detection means for quality control and process optimization in semiconductor manufacturing.