In the context of international science and technology competition, foreign enterprises exploit patent appropriability mechanisms to implement technological locking strategies against China’s critical industries, leading to path dependence and triggering a technological blockade crisis. By constructing a patent dataset for China’s integrated circuit (IC) manufacturing industry, this study reveals the path dependence effect arising from foreign firms’ patent appropriability in China. The results show that foreign companies use patent appropriability to hinder the granting of patents to subsequent innovators, thereby reinforcing path dependence. Foreign firms tend to adopt technological locking strategies under conditions of tense Sino-foreign relations, declining bilateral trade, reduced openness, and a growing intellectual property trade deficit. Furthermore, these firms concentrate on midstream technological segments of the IC manufacturing sector, selecting highly original patents as tools for these locking strategies. This study provides insights for China to counter foreign technological locking strategies and even technological blockade policies in its critical industries.