Abstract: In response to the increasing construction of engineering involving railways and the continuous improvement of the demand for anti-intrusion limit monitoring, this paper designed an anti-intrusion limit monitoring system for engineering involving railways based on the fusion technology of laser radar and camera. The system adopted a three-level architecture consisting of the monitoring center of the railway group company, the construction site monitoring center, and the on-site anti-intrusion limit monitoring equipment, implemented precise monitoring and alarm for intrusion limit events in engineering involving railways. The paper elaborated on the specific functions and key technologies of the system, and deployed and tested the system in an engineering project involving railways to verify its performance, which had promotional value.