This paper addresses the need for pipeline collision avoidance in construction scenarios such as cylinder-to-pipeline conversions in old residential areas, road expansions, and infrastructure配套 in new developments. To prevent damage to pipelines during excavation, we have designed a real-time, high-precision automated warning system. By integrating GNSS, IMU, and a GIS monitoring system, the system acquires the spatial coordinates of the excavator’s bucket tip and performs real-time analysis against a preloaded three-dimensional pipeline map database, calculating the Euclidean distance to the nearest pipeline. Based on the control requirements and minimum protection zones for transmission and distribution pipelines, safety thresholds are established, simultaneously triggering local audio–visual alarms and remote tiered alerts. The system’s effectiveness was validated through simulations at Wuxi China Resources Gas and in actual construction sites. Experimental results demonstrate that the system achieves sub-meter positioning accuracy within 0.5 meters, with an alarm response latency of less than 200 milliseconds. It accurately issues warnings when the excavator enters the预警 or danger zones, while maintaining false alarm and missed alarm rates both below 5%, significantly outperforming conventional manual warning methods. This study confirms the feasibility and efficiency of combining integrated positioning with GIS analysis in the field of construction machinery safety monitoring. The proposed system offers a digital, real-time solution for underground pipeline protection, holding substantial practical value for enhancing construction safety and reducing economic losses and social risks.