In order to realize the visual monitoring, regulation, and control of environmental parameters in agricultural greenhouses, a greenhouse monitoring system and a virtual reality (VR) digital cockpit based on Unity 3D and LoRa IoT are researched and developed. An IoT containing multi-region environmental parameter sensing nodes and control nodes is constructed based on LoRa wireless communication technology, and deployed ThingsBoard on private cloud server to manage the data and devices. Using Unity3D to develop digital models based on the physical objects of the actual agricultural greenhouses, building a VR digital agricultural greenhouse, and interacting with the cloud platform via HTTP protocol, thus, the interaction between material reality and virtual reality between VR digital agricultural greenhouses and actual agricultural greenhouses is realized. After experimental testing, the developed agricultural Internet of Things system can correctly detect and upload data, the measurement repeatability of each parameter is better than 14%, the delay of one data update of the virtual reality digital cockpit is less than 200 ms, enabling real-time, intuitive, clear, and immersive monitoring of various parameters in the agricultural greenhouse. The virtual reality digital cockpit technology has an important application potential.