It's a code word between hostages and rescuers. Dry-fried Niuhe comes from the TV series The Knockout. In the play, Li Xiang leads all police officers to participate in the grand meeting, and the task is to rescue the hostages. Li Xiang made careful arrangements and divided the police officers into the young eagle group and the sparrow group. Everyone split up and dealt with the robbers. When the young eagle group rescued the hostages, they exchanged signals with the hostages. The hostages needed to tell the secret code of dry-fried Niuhe, and the rescuers needed to tell the unique secret code. To make sure the hostages are on their side.