You require a Visa for an internship in China. You need to apply for a Visa in person at the respective embassy or consular in your home country. The requirements might vary depending on your home country.
Documents and requirements:
• Valid passport
• Application form ( can be downloaded on the respective website of the embassy
• Invitation of the respective Ministries, Provincial Governments or eligible institution
• Work Permit for Aliens issued by the Chinese Labor Ministry or the original of Foreign Expert's License issued by the Chinese Foreign Expert Bureau (Original and Copy)
• Visa Fee
For further information please check the website of the Chinese Foreign Affairs office: www.fmprc.gov.cn