The Admiral Liu in the novel " The First Son-in-law " referred to the background of the Qing Dynasty. In the novel, Admiral Liu was a wealthy warlord. He had made achievements in politics, economy, culture and other aspects through his economic strength and political influence. At the same time, he was also a high-ranking general in the Qing Dynasty army. He had led the army to participate in many wars. Therefore, in the novel, Admiral Liu was in the Qing Dynasty.