The water splashing ceremony in the engagement ceremony is an important part of the marriage custom of the Yi people, and it has rich cultural connotations.Taking the engagement ceremony of the Yi people in Tong'an Town, Huili County, Sichuan Province as an example, combined with the ritual process theory of anthropologist Victor Turner, the reason for the splashing ceremony in the engagement ceremony was analyzed. In the engagement ceremony of the Yi people, the water splashing ceremony dominated by women reflects the phenomenon of "structure" and "anti-structure" in the ceremony. Based on the theoretical analysis of the ritual process, it proves that the phenomenon of the female group splashing the male group is reasonable in the ritual. However, when analyzing the cause of the formation of rituals, it is necessary not only to explore from the perspective of structural tension,but also explain it from the principles outside the social structure, such as water worship, playful behavior and resistance and acceptance, to explore the deeper meaning of the engagement deadline in Yi people.