It is difficult to successfully detect the false data injection attacks against the linear state estimation based on phasor measurement techniques in power systems.Here,we propose an intelligent method to detect false data injection attacks.First,the auto-encoder is used to extract the features of the power grid measurement data,which is done repeatedly to gradually reduce the feature dimension.Then the finally extracted feature is subjected to supervised learning through the Softmax layer,so as to obtain an attack detection algorithm based on stacked auto-encoders.Second,the attack detection approach is improved through noise reduction to solve the over fitting of auto-encoders.Finally,the proposed method is simulated and verified by IEEE-118 node test system,and the results show that the proposed attack detection method has high computational accuracy and efficiency.