A sodium cyanide evaporation device relates to the technical field of applied chemical industry. The problems of non-uniform temperature in the kettle body and easy loss of sodium cyanide during evaporation are solved; the evaporation kettle comprises an evaporation kettle body, a fixed seat and a motor are arranged at the top of the evaporation kettle body; a first bearing is arranged in the fixed seat; a stirring pipe is sleeved in the first bearing; gears are arranged on main shafts of the stirring pipe and the motor and are meshed with each other; a second bearing is arranged at the upperend of the stirring pipe; a water adding pipe is sleeved with the second bearing, a sealing bearing is arranged at the bottom of the evaporation kettle body, the interior of the sealing bearing is sleeved with a stirring pipe, the stirring pipe is communicated with a multi-layer bent heating pipe, a drainage pipe is sleeved with the sealing bearing, a gas phase outlet is formed in the top of the evaporation kettle body, and a multi-layer filter screen is arranged in the gas phase outlet and connected with a heater; according to the device, stirring and heating are combined, so that sodium cyanide in the evaporation kettle body can be uniformly heated, meanwhile, sodium cyanide in exhausted gas is remarkably reduced, and good economic and environment-friendly benefits are achieved.