The high-reliability dissolved gas online monitoring product for transformer oil, developed based on laser photoacoustic spectroscopy technology for the State Grid and national energy security applications, enables continuous online detection of characteristic gases—including H₂, CO, CO₂, CH₄, C₂H₂, C₂H₄, and C₂H₆—as well as the moisture content in transformer oil according to predefined intervals, providing comprehensive real-time monitoring and early warning capabilities for transformers.