The invention discloses a method for discriminating reservoir fluid by establishing a gas logging chart on the basis of discriminant analysis, relating to the technical field of oil and gas exploitation and development. The method includes the steps of: a, collecting the gas logging peak value data and the oil test results in an oil test completion well; b, according to the categories of the oil test results, grouping the gas logging peak value data of the logging display sections which have the same category of oil test results; c, establishing discrimination factors by taking the gas logging peak value data of the logging display sections as a base; d, selecting the established discrimination factors, and formulating discrimination functions which can effectively discriminate the property of the fluid on the basis of discriminant analysis; and e, according to the coincidence rates of the formulated discrimination functions, preferentially selecting two discrimination functions with the highest coincidence rates to be used as x axis and y axis to establish a gas logging chart to discriminate the property of the reservoir fluid. The method disclosed by the invention solves the problem that conventional gas logging charts are difficult for effectively discriminating the reservoir fluid, so the dominant regions of different fluids can be well marked out.