The invention discloses a brain electrical signal EEG feature extraction method based on a convolution neural network, comprising the following steps of: S1, designing a brain electrical data collection experiment scheme of color recognition; and setting a cycle with three test pictures and three transitional pictures in full black, wherein the time of the test pictures is t1, the time of the transition pictures is t2, the test pictures in each cycle are separately red, green, blue primary colors, and the red, green, blue primary colors appear in random order, so that the time of one cycle is3t1 + 3t2, each subject is tested N cycles, and the total time is N*(3t1 + 3t2). The purpose of setting the transitional pictures is to eliminate the visual residue when switching the test pictures. The invention avoids the problem of extracting the orders in the brain electrical signal features by using an AR model, and the features extracted by the convolution neural network obtain the satisfactory results in color recognition.