Abstract
With the continuous growth in the demand for safety assurance in major projects and monitoring in extreme environments, sensor technology is facing challenges in harsh working conditions such as high temperatures, high pressures, and complex liquid media. This article focuses on typical complex environments such as underground and marine environments, systematically reviewing the basic principles, performance characteristics and the latest application progress of mechanical, optical and acoustic sensors in complex environments, and deeply analyzing their applicable boundaries and technical bottlenecks. The transmission mechanism of sensor data and the system architecture of the engineering monitoring and early warning platform were further explored, and their key roles in real-time perception and intelligent decision-making were evaluated. Finally, the core challenges and development opportunities currently faced by complex environmental sensing systems are summarized, and the future development directions, such as multi-parameter fusion, autonomous perception and edge intelligence, are prospected. This paper aims to provide a systematic theoretical basis and engineering practice reference for the design of sensors and the construction of monitoring systems in extreme environments.