A pulse spectroscopic scheme based on dye dilution and an excretion test was developed to overcome the shortcomings of conventional blood dye concentration measuring method in complex operation, invasive treatment and non-continuance. Firstly, Indocyanine Green(ICG) was intravenously injected and a finger clip sensor was used to extract spectral signals of fingertips for a sufferer. Then, by recording the dye dilution curve simultaneously , the algorithm to isolate ICG absorption spectrum from the disturbance of peripheral arterial blood was implemented. Finally, the ICG plasma disappearance rate K, 15 min retention rate R15and other hepatic hemodynamic parameters were deduced by analyzing the semi-logarithmic dye concentration graph. Combining a lab-VIEW software platform with an adaptive differential threshold method, proposed scheme eliminates the interference come from the hemoglobin absorption spectrum and baseline drift, improves the measuring accuracy greatly, and the average measurement error of K is less than 0.008. This method is great value to not only the assessing hepatic functional reserve at pre-operation, intra-operation, post-operation, but also providing a way to monitor some middle variables for clinical research purposes.