Paeonia delavayi is a woody plant of the peony group, endemic to China, and has been a traditional medicinal herb since ancient times, as well as a valuable resource for breeding new peony species. Predicting the contemporary and future distribution patterns of Paeonia delavayi in suitable habitats under climate change conditions can provide scientific data to support the establishment of effective conservation. The potential distribution area of the endangered medicinal plant Paeonia delavayi was simulated by the Maxent model. The contribution rate of environmental factors and the knife-cut method were used to test and analyse the factors affecting the distribution of Paeonia delavayi. The response curves were used to determine the appropriate values of environmental factors. The AUC value for Paeonia lactiflora was 0.990, indicating excellent model accuracy. The current total suitable habitat area of Paeonia delavayi was 41.58×104 km², located in the southwest region of China. The high suitable habitat area of Paeonia delavayi was 3.71×104 km², accounting for 8.92% of the total suitable habitat area, mainly distributed in the south of Sichuan, north of Yunnan, and south of Chongqing in thin strips. The most important environmental factor affecting the geographic distribution of Paeonia delavayi is isothermal (Bio3). Under the future climate change scenario, the total suitable habitat area of Paeonia delavayi will increase significantly, and the area of highly suitable habitat will also increase. The centroid of the highly suitable area tends to migrate to high latitude and northwest direction, and the migration range is greater under the high-concentration emission scenario. The research results can provide a theoretical basis for the in-situ protection and sustainable utilization of Paeonia delavayi.