The Ultra-High Voltage (UHV) pillar porcelain insulator, a critical component in power systems, is prone to brittle fracture due to stress concentration and internal cracks, posing safety risks. To mitigate this, real-time load monitoring of these insulators is imperative. This paper presents a novel online load monitoring system for UHV pillar porcelain insulators utilizing laser ultrasonic technology, coupled with an advanced correction algorithm for air and surface wave interference during synchronous excitation. The theoretical foundation for laser ultrasonic stress detection on porcelain insulators is substantiated through simulation analysis. The hardware and software components of the system have been meticulously designed and developed. Experimental results demonstrate the system′s high efficiency in online monitoring, achieving an average error of 16.20% between measured and actual bending loads. This accuracy meets engineering detection requirements, indicating the system′s promising application potential for enhancing the safety and reliability of UHV power systems.