Brecht believes that the audience in traditional drama is often attracted by the plot and forgets that they are watching the play. He believes that this situation will lead to the overflow of audience emotions and weaken the social criticism of drama. Therefore, Brecht put forward the "estrangement effect", through a series of techniques (such as actors telling lines directly to the audience, using abstract stage scenery, etc. Let the audience keep an objective distance, not be attracted by the plot, and think more rationally about the information conveyed in the play.