The invention discloses a method for preparing germinated brown rice rich in gamma-aminobutyric acid. The method comprises the following steps: step 1, pretreating brown rice raw material by means of freezing stressing; step 2, washing the brown rice obtained in the step 1 by water and draining; step 3, soaking the brown rice obtained in the step 2 in a soaking solution; step 4, geminating the brown rice obtained in the step 3 and then drying at a low temperature to obtain a germinated brown rice finished product. According to the method disclosed by the invention, the soaking solution is added with tea polyphenol in order to play a quite good inhibition effect on microorganisms and floras during germination, so that the content of the gamma-aminobutyric acid in the germinated brown rice can be increased and the taste of the germinated brown rice can be improved as well.