The invention relates to a sealing process of a sealing device on an oil-gas outlet of an oil shale rotary type dry distillation furnace. During a production process of the oil shale rotary type dry distillation furnace, a sealing sleeve pipe seals the periphery of the oil-gas outlet of the rotary type dry distillation furnace through oil immersed graphite wire rods at two sides of a nitrogen injection ring sleeve; a nitrogen storage tank injects nitrogen into four nitrogen injection ports on a pipe wall of an oil-gas transmission pipe through a pipeline; and the nitrogen continuously passes through the four nitrogen injection ports to enter a nitrogen cavity so as to be sequentially injected into four holes in an outer wall of the sealing sleeve pipe, so that the nitrogen injection ring sleeve keeps the nitrogen cavity to be full of nitrogen so as to supplementarily seal gaps of the oil immersed graphite wire rods. According to the sealing process of the sealing device on the oil-gasoutlet of the oil shale rotary type dry distillation furnace provided by the invention, the oil immersed graphite wire rods are used as packing seal media, and are used for sealing a gap between the oil-gas outlet of the rotary type dry distillation furnace and the sealing sleeve pipe when the oil-gas outlet of the rotary type dry distillation furnace rotates, and the nitrogen is used as an inertgas to form a protection air curtain so as to supplementarily seal the oil-gas transmission pipe, so that the production safety of oil shale dry distillation through the rotary type dry distillation furnace can be ensured.