Abstract: To identify methods of enhancing data center power utilization and addressing the practical challenges encountered by large data centers, including the aggregation of infrastructure power data and the management of discrete data functions, This study designed and implemented a data center energy efficiency online monitoring system based on IoT technology and multi condition evaluation. The system integrates Lora wireless communication meters, temperature and humidity sensors, and portable gateway modules to build a three-layer architecture of hardware, server, and web, achieving real-time collection, transmission, and visual analysis of energy consumption and environmental parameters in data centers.By establishing a comprehensive energy efficiency assessment management system, it creates a unified online platform for energy consumption measurement, energy efficiency calculation, and assessment of large data centers. According to the data monitoring and calculation of a data center, the calculated value of the common PUE is 1.48, while the average PUE of the working condition method is 1.49. The experimental results show that the system has significantly improved the accuracy of energy efficiency data collection, dynamic analysis and evaluation, which provides strong technical support and scientific basis for the energy efficiency optimization and management of data centers.