The remote SF6 density relay is widely used in high-voltage circuit breakers, high-voltage cables, high-power transformers, high-voltage transformers and other SF6 electrical engineering equipment to monitor and monitor the SF6 gas density in closed containers. Adopting mechatronics technology, it has the functions of indicating value, contact and electrical signal and temperature compensation. The data collection and remote monitoring of SF6 gas density, temperature and pressure are realized. It can also be used for new substation supporting and intelligent transformation of existing substation.