Final answer:
The Ming Dynasty limited outside influence in China by restricting trade and banning private foreign trade. They aimed to protect China from outside ideas and challenges to the emperor's rule.
Step-by-step explanation:
The Ming Dynasty tried to limit outside influence in China by implementing various policies and restrictions. One of the main ways they did this was by limiting trade with foreign countries and allowing only visits by vassals from tributary states. The Ming dynasty also banned private foreign trade and destroyed ocean-going ships to discourage contact with foreigners. These measures were intended to protect China from outside ideas and potential challenges to the emperor's rule.