Does intangible cultural heritage need to be capitalized in English?

No need. Intangible culture belongs to a technical term. In English, only the first letters of titles and sentences need to be capitalized, so the word intangible culture doesn't need to be capitalized, just lowercase normally. Intangible cultural heritage refers to various forms of traditional cultural expressions handed down from generation to generation by people of all ethnic groups and regarded as part of their cultural heritage.