With the development of intelligent technology, portable warning fence system based on artificial intelligence (AI) recognition and sensor collaboration has become an emerging security protection technology. This study proposes a portable warning fence system that combines multiple sensors with AI image recognition technology, aiming to improve target recognition accuracy and response speed, while enhancing the environmental adaptability of the system. Through multi-sensor data fusion and AI algorithm optimization, this system can accurately identify dynamic targets in complex environments, and can work stably in extreme weather and low light conditions. Experimental results show that the accuracy of the system in clear daytime and dim night environments is 98.2% and 96.8% respectively, the response time is controlled within 150 ms, and the system load is about 23%. In addition, the system can still maintain efficient operation when detecting complex backgrounds and dynamic targets, showing excellent recognition ability and stability. The warning fence system based on AI recognition and sensor collaboration provides an efficient, flexible and widely applicable solution for the future intelligent security field.