The reason why Tao Yuer is Tao Sanniang's previous life is because Tao Yuer is similar to Tao Sanniang in character and appearance. In the novel "Mrs. Gluttonous": Tao Yuer is a subordinate of Tao Sanniang. In the process of getting along, people found that Tao Yuer and Tao Sanniang were similar in character and appearance from a distance, so there was a saying that Tao Yuer was Tao Sanniang's previous life. Therefore, Tao Yuer is a previous life of Tao Sanniang, because Tao Yuer is similar to Tao Sanniang in character and appearance.