An electrified on-line dehumidifying and purifying system of sulfur hexafluoride electric equipment comprises a gas inhaling drying and purifying pipeline, a compressing system and a gas exhaling drying and purifying pipeline, wherein the compressing system comprises two compressed gas pipelines which are arranged in parallel, the gas inlet ends of the two compressed gas pipelines are connected with a gas outlet of a storing tank on the gas inhaling drying and purifying pipeline, and the gas outlet ends of the two compressed gas pipelines are connected with a gas inlet end of the gas exhaling drying and purifying pipeline. The electrified on-line dehumidifying and purifying system can absorb water, decomposed products and floating dust in SF6 gas of high-voltage electric equipment which runs and finish the dehumidifying, purifying and recyling of the sulfur hexafluoride gas. The electrified on-line dehumidifying and purifying system has double absorbing and purifying functions, ensures exhaling and inhaling processes, and can well dry and filter the SF6 gas. The normal running of the high-voltage electric equipment, such as a circuit breaker and a high-voltage switch, are not affected in the purifying process, and online continuous running is realized.