The invention discloses a method for rapidly identifying peanuts doped in raw materials for walnut milk production. The characteristic that different types of plant protein milk have respective special fatty acid compositions and contents is utilized, and the doping of peanut milk can be determined through determination of the fatty acid composition and contents in walnut milk to be identified and comparison of standard walnut milk. The method for determining the fatty acid composition and contents comprises the following steps: extracting fat in the walnut milk through n-hexane, obtaining n-hexane-fat solution through centrifugal separation, forming a volatile methyl ester derivative through methyl ester treatment with potassium hydroxide-methanol solution at the room temperature, analyzing the volatile methyl ester derivative with a gas chromatograph, and determining the composition in the area normalization method. By adopting the method, the peanut milk doped in the raw materials for walnut milk production can be identified and tested within 60 minutes. Moreover, the method is accurate and reliable, the operation is easy, the testing cost is low, and the method can be universally promoted and applied.