这是一样的，因为你是在测试集上训练，而不是在训练集上.不要那样做，只需在训练集上训练:

It is the same because you are training on the test set, not on the train set. Don't do that, just train on the training set:

history = model.fit(x_test, y_test, nb_epoch=10, validation_split=0.2, shuffle=True)

变成:

history = model.fit(x_train, y_train, nb_epoch=10, validation_split=0.2, shuffle=True)