Prunus mume has been cultivated for more than three millennia with important edible, ornamental, and medicinal value. Due to its sour taste, the Prunus mume fruit (called Meizi in Chinese and Ume in Japanese) is not very popular compared to other fruits. It is, however, a very favorite food for the Bai people living in Eryuan County, Dali of Yunnan, China. The local people are masters of making various local products with plum in different ways. In this research, we conducted field investigations in Eryuan County using ethnobotanical methods from August 2019 to July 2021, focusing on the Prunus mume (for its edible fruits). A total of 76 key informants participated in our semi-structured interviews. The survey recorded 37 species (and varieties) belonging to 11 families related to the Bai people’s Meizi-consuming culture. Among them, there are 14 taxa of plum resources, including one original species and 13 varieties. These 37 species are either used as substitutes for plum due to their similar taste or as seasonings to improve the sour taste of plum. The higher Cultural Food Significance Index value implies that Prunus mume, Chaenomeles speciosa, Phyllanthus emblica, Prunus salicina, and Chaenomeles cathayensis have high acceptance and use value in the Bai communities. Among the various local products traditionally made by the Bai people, carved plums, preserved plums, perilla-wrapped plums, and stewed plums are the most famous and popular categories in the traditional markets. Currently, the plum business based on the traditional Meizi-consuming culture of the Bai people is already one of Eryuan’s economic pillars. This study showed that plums play an important role in expressing the local cultural diversity, and they also help the local people by improving their livelihood through their edible value. In turn, for the sustainable use of plum resources, the Bai people positively manage local forests through a series of measures to protect the diversity of plum resources and related plant communities.