The invention discloses a polybutylene small bulk production emergency device, and belongs to the technical field of polybutylene production. The device comprises a polymerization kettle, wherein a water injection pipe is arranged at the top of the polymerization kettle; the polymerization kettle is communicated with a water injector through a water injection pipe; a water inlet valve is arranged on the water injection pipe, and is used for controlling water to be injected into the polymerization kettle; a valve a is arranged on the water injection pipe, close to the polymerization kettle; a water feeding valve, an emptying valve and a nitrogen blowing pipe are arranged at the top of the water injector; the nitrogen blowing pipe is communicated with the water injection pipe, and is provided with a nitrogen blowing valve; a nitrogen main pipe is communicated with one side of the water injector; a nitrogen valve is arranged on the pipe, communicated with the water injector, of the nitrogen main pipe, the spraying state of water is reinforced through the nitrogen blowing pipe so as to improve the inactivating effect of water; a steam main pipe is communicated with the water injection pipe; and a valve c is arranged on the pipeline between the steam main pipe and the water injection pipe.