As the pace of digital oilfield construction continues to accelerate, the application of cloud-based intelligent video monitoring in oilfields has become a hotspot. The existing video monitoring system has the defects of difficult client deployment and poor system expandability, and the intelligent detection mainly relies on passive video monitoring to cope with the potential safety hazards at the operation sites. In addition, the monitoring log data cannot be effectively archived for management and comprehensive analysis. To meet the actual needs of oilfields, this study firstly designs the overall architecture of the cloud-based intelligent monitoring system, with the shortcomings of the existing monitoring architecture taken into consideration. Then, risk factors at the operation sites are detected and analyzed by intelligent video detection means. Finally, the hazard logs and other data generated by the system are managed and analyzed to provide decision support for site safety management. At present, the system has been deployed to an oilfield and has successfully passed the function and performance tests. It is of great significance for the improvement in effectiveness and real-time performance of monitoring, the enhancement of ability to deal with emergency events, and the safe operation and production in oilfields.