I know which ethnic minority in China has a traditional festival of Water-splashing Festival.

Songkran Festival is a traditional festival of Dai people in Yunnan, China. Dai people, also known as "Dai-Tai people", are a minority in China and the most populous Dai people in the world.

Dai Tai originated in the western part of Yunnan-Guizhou Plateau, and established political power in Yunnan-Guizhou Plateau many times. Later, due to the oppression of the Central Plains Dynasty and other nationalities, it gradually moved to Indochina Peninsula and South Asia subcontinent. Now it is distributed in Thailand, Laos, Myanmar, India, Viet Nam, China, Cambodia and other countries, with a total population of about 68 million, 47 million in Thailand, 5 million in Laos, 8.5 million in Myanmar and about10 million in India.

In China's historical records, Dai Tai was called Ailao, Shan, Wuman, Baiman, Baiqun, Jinya, Hei Chi, Baiyi, Boyi and Baiyi successively. Before the Second World War, under the impetus of the kingdom of Siam, the international community began to collectively refer to the Dai and Thai nationalities distributed in various countries as "Thais"; After World War II, governments in their respective territories were named after Dai and Thai, and they are still called "Thai" in Thailand, Cambodia, Viet Nam and other countries, "Lao" in Laos, "Shan" in Myanmar, "Assam" in India and "Assam" in China.