The utility model provides a sulfur hexafluoride switchgear synthesizes device of on -line monitoring and control installs partial discharge on -line monitoring system, sulfur hexafluoride gas pressure on -line monitoring system, temperature on -line monitoring system in sulfur hexafluoride switchgear, installation temperature and electric current on -line monitoring system in the heat preservation system, and at the meteorological on -line monitoring system of equipment externally mounted, on -line monitoring system is all with data transfer to monitoring and control center, the monitoring and control center judges whether open the heat preservation system through internal program, perhaps whether sends alarm instruction to control sulfur hexafluoride switchgear and heat preservation system ensure that sulfur hexafluoride switchgear well moves. The utility model discloses utilize advance on - line monitoring method, carry out on -line monitoring and control to sulfur hexafluoride switchgear and heat preservation system to performances such as the validity of sulfur hexafluoride switchgear under extremely cold environment, reliability, security are improved greatly, and its life can be prolonged by a wide margin.