The invention discloses a playback speech detection method. At a training stage, a first variation coefficient vector, a normalized first cepstrum feature matrix, a second variation coefficient vectorand a normalized second cepstrum feature matrix of each speech sample in a speech database are firstly acquired as four kinds of features; the four kinds of features of all positive samples are theninputted to a GMM model for training, four positive sample feature models are obtained, and besides, four negative sample feature models are obtained; at a testing stage, four kinds of features for to-be-detected speech are acquired in the same way, the kinds of features are inputted to the corresponding positive sample feature models and the negative sample feature models respectively, and four likelihood ratio scores are obtained; and according to the four likelihood ratio scores, a final score is obtained, and through compairing the final score and a judgment threshold, whether to be a playback speech is judged. The playback speech detection method is not only limited to a text-related voiceprint authentication system, and has the advantages of low equal error detection possibility, strong robustness and relatively low calculation complexity.