Vietnamese were detained in China without a visa. Can I get a marriage certificate to come to China when I return to Vietnam?

Of course. According to the relevant information of China Travel Service. Com, if Vietnamese are repatriated, they need to be banned from entering China within five years after repatriation. However, if Vietnamese marry China citizens, they can apply for marriage immigration according to relevant regulations. When applying for marriage immigration, you need to provide relevant certification materials, which can only be processed after being audited by relevant departments and meeting the requirements. Therefore, if they meet the requirements, Vietnamese can still come to China to get married after repatriation.