Written by Liu Lian Zi, Ruyi's Royal Love in the Palace is an online novel about the competition of the imperial harem and a sequel of The Legend of Zhen Huan. With symbols of Chinese culture, dietetic writing is an essential element in modern novels. It appears the same in Ruyi's Royal Love in the Palace. Through the dietetic writing, the main storyline is developed, and the essence of imperial harem novel is highlighted. This paper consists of two parts- "diet and gender relationship", the dietetic writing serves as the main storyline, and "power struggle", the essence of the imperial harem competition. The two parts analyze the relationship between dietetic writing and the plots, summing up the dietetic writing commonly seen in imperial harem novels, and inspect the patriarchy hidden in Ruyi's Royal Love in the Palace. The research of the system and pharmacy is not expertly done in Liu Lian Zi's work; however, how she presents the palace has reached the readers' expectation. What's more, the plots settings are similar to the dilemmas that female readers have encountered in Chinese society. These reasons have made Ruyi's Royal Love in the Palace a popular wor