The International Silk Union (ISU) is an international, specialized, non-profit social organization voluntarily joined by silk-producing and consuming countries' enterprises and related organizations worldwide. It was initiated by CATHAYA Group in 2015. The establishment of the International Silk Union aims to promote mutual exchange and cooperation among the silk industries of different countries, driving progress and development in international silk culture, education, research, design, production, standards and testing, trade, and consumption. It provides a favorable platform for communication and collaboration within the international silk industry.

The current chairing organization of the International Silk Union is Zhejiang CATHAYA International Co., Ltd., and the union's secretariat is located in Hangzhou, China.

Since the inaugural members' congress held in October 2015, nearly 140 companies and organizations from 24 countries and regions, including China, Italy, France, Switzerland, Brazil, Poland, Japan, Turkey, Thailand, India, Vietnam, Cambodia, Myanmar, Indonesia, Singapore, the United States, Australia, Uzbekistan, Bangladesh, Laos, Iran, Pakistan, Romania, and Hong Kong (China), have joined the alliance. Currently, the union has 11 vice-chairing organizations and 46 executive council member organizations. Notably, national-level industry organizations such as the Italian Silk Association, French Silk Association, Brazilian Silk Association, Vietnam Sericulture Association, Cambodia Silk Industry Development Promotion Committee, Iran Silk Research Center, and China Textile Engineering Society have joined, extending the influence of the union to major silk enterprises and research institutions worldwide. In 2020, the International Silk Union was included in the International Organizations Yearbook by the Union of International Associations (UIA), becoming the first international silk industry organization with its secretariat based in China recognized by the UIA. In 2021, the International Silk Union signed a strategic cooperation agreement with the Inter-governmental International Organization International Sericultural Commission (ISC), establishing a dialogue partnership.

Since its establishment, the International Silk Union has been committed to the principles of "exchange, cooperation, and joint development." It actively engages in international exchanges and cooperation by organizing international conferences, facilitating international visits, and establishing professional committees in the field of silk, including committees dedicated to "historical culture," "fashion design," "education and research," and "technological innovation." The union has set up the official website and a media matrix called "World Silk Net," organizes the publication of the ISU News magazine, and co-hosts the professional journal "Silk" in collaboration with CATHAYA Group. Under the leadership of CATHAYA Group, efforts are consistently made to promote the integration and development of international silk culture and industry.