Abstract: In view of the difficulty in identifying the reservoir fluid properties of the Yan’an Formation in the Huanxi–Pengyang Area, beginning with the conventional interpretation difficulties of logging and mud logging, the Fisher discrimination method in SPSS software was introduced, with the concept of Big Data, the logging/mud logging parameters were deeply mined. Considering the recognition rate and separation degree, 15 parameters of reservoir fluid sensitivity were selected to identify the classification of Fisher non-standardized discriminant function, and the accuracy of fluid identification could reach 92.8%. Functions F₁ and F₂ were selected for their large contribution rate and intersected to plot the interpretation chart, and the identification rate of the chart was 89%. The interpretation chart was applied in the fluids interpretation and evaluation of 10 layers in 9 wells of Huanxi–Pengyang Area with a coincidence rate of 80%, and no valuable layers were missed. The application results showed that the Fisher discriminant method is suitable for high accurate identification of reservoir fluid properties in similar reservoirs, and it is worthy of wide adoption.