Chinese enterprises have frequently encountered patent war in overseas markets in recent decades, which has severely shocked their international operation. Patent war is attack and defense behavior around the ownership and utilization of patents, and its purpose is to strike competitors and gain business interests or competitive advantages. Patent war has become a serious challenge for Chinese enterprises. The US market is the main battleground in the global patent war. We carry out an empirical study on the patent war encountered by Chinese enterprises in the US market. The results show an inverted U-shaped relationship between relative patent strength and patent war. NPE prefers to initiate patent war compared to conventional entities. Transfer times and the number of claims are significantly correlated with patent war. Technological involution has a moderating effect on the above relationships. Therefore, it is necessary to strengthen the application and layout of international patents, and improve patent strength to resist the patent war in overseas markets. The patent war risk in the field with technological involution should be paid higher attention, and patent warning should be implemented for high-risk entities and patents.