In this research project, we aim to build a long-range (LoRa)-based Internet of Things (IoT) secure localization system and application based on multisensor fusion calculation. The LoRa technology is used to design a network security system and immediately address the computing system, where the purpose is to develop a network server host that collects and processes position signals from the multisensing signal collection and analysis processing module, and instantly detects location by network nodes through the sensors cloud, the Arduino UNO high-level development platform, and the multisensor fusion computing workstations, which send the results to the central monitoring system through the wireless devices of the LoRa network. The secure localization computing chip outcome, as developed in this project, can be used in the domains of energy management, environmental management, information management, factory monitoring, and renewable energy management. The system of this project comprises LoRa hosts, which receive signals from various nodes and are connected to a multisensor fusion arithmetic system through a wireless network. To sum up, in this study, we emphasize using multisensor fusion computing technology to implement a secure localization system of a wireless sensor network (WSN), and we consider using the embedded system and LoRa technology to develop a monitoring system for factory fire control, anti-theft, energy, information, and security based on secure localization. In this study, we cross domains and integrate related engineering automation, network security technology, multisensor fusion calculation design, and the LoRa localization technique, and the research findings are expected to contribute to the network security of the defense industry and research on the LoRa IoT localization system.