Characterized by low cost, low-power consumption and flexible deployment, long range radio (LoRa) is able to effectively meet the communication requirements of many scenarios in power Internet of Things. At current stage, the lack of analysis tools and research methods to evaluate the performance of LoRa in power Internet of Things makes it difficult to carry out related researches and large-scale applications. Therefore, by comprehensively analyzing the LoRa communication network protocol, this article establishes LoRa communication message information and critical equipment models based on OPNET simulation software, so as to provide an effective analysis tool for quantitative analysis of the application performance of LoRa. Furthermore, considering the business scenarios of low-voltage centralized automatic meter reading and environmental monitoring in power Internet of Things, this article also completes quantitative analysis on real-time performance, reliability and business support capability of LoRa communication network through multi-scenario LoRa communication performance simulation, including business parameters configuration, quantity of devices and access distance, etc. The simulation results verify the effectiveness of the modeling method. Meanwhile, the corresponding evaluation conclusions can also provide us scientific and reasonable guidance for the engineering application of LoRa in power Internet of Things and other fields.