Given the critical role of calcium gluconate in clinical detection, we have designed a detection method based on terahertz time-domain spectroscopy (THz-TDS), which enables rapid, non-destructive, and high-precision spectral analysis. Initially, calcium gluconate film samples were prepared using a compression method with a mass percentage ranging from 2.5% to 20%. Additionally, solutions with molar concentrations of 5 to 20 mmol/L were prepared using a water-glycerol mixture as the solvent. These samples were analyzed using a self-constructed THz-TDS transmission system under room temperature and vacuum conditions. Subsequently, Fourier transform was applied to convert the time-domain signals into frequency-domain spectra, from which the absorption coefficient and refractive index spectra were extracted. A quantitative relationship between concentration and spectral parameters was established through linear fitting. The experimental results indicate that the film samples exhibit distinct absorption peaks at 1.19, 1.39, 1.66, 1.87, and 2.29 THz. Data analysis reveals that the absorption coefficients at these peaks demonstrate a clear linear relationship with the sample’s mass percentage, particularly at 1.66 THz, where the linear fitting degree reaches 0.991. For solution samples, due to the strong absorption characteristics of the solvent, the refractive index spectrum analysis shows a good linear relationship between the refractive index and molar concentration at 1.66 THz, with a fitting degree of 0.987. These results suggest that this method not only allows for effective quantitative analysis of the absorption properties of samples but also provides accurate evaluation of the dispersion (refractive index) properties. When combined with miniaturized THz-TDS equipment and artificial intelligence algorithms, this technology demonstrates significant scientific research value and application potential in clinical blood calcium monitoring and drug authenticity identification.