Through the characterization of the two parameters of intracellular and extracellular fluids, it is possible to predictordiagnose certain diseases in the human body. When calculating these two values using traditionalbioelectrical impedance spectroscopy, human bioelectrical impedance data of hundreds or even thousands of frequency points is required, and the data collection and processing are extremely complex. Based on the Cole-Cole theory, this paper proposes a method forthestudyofintracellularand extracellularfluidsbycombiningthethree-spectralpointmethod and the Moisslequation. In this method, only three frequency points of bioelectricalimpedance values need to be collected and applied, thebioelectricalimpedanceparameterscan be extracted, and theintracellularand extracellularfluids can be further calculated. The results verify that the results obtained by this method are consistent with these gained by the commonly used bioelectricalimpedance spectroscopy method, and the time taken to collectand process the data is only 12.73% ofthatofthe traditionalmethod.