The invention discloses a stripping device and a stripping method for butyl rubber. The device comprises a flash evaporation tank, the flash evaporation tank is provided with a stripping tower, and the bottom outlet of the flash evaporation tank is connected with a rubber liquid conveying pump and then is connected to the middle part of the stripping tower, a sleeve mixer is arranged at the upper inlet of the flash evaporation tank, and a stirrer is arranged in the flash evaporation tank. The method comprises the following steps: a reacted butyl rubber mixture is stripped by steam by using a solvent, methyl chloride used in a reaction of the butyl rubber and unreacted isobutylene and isoprene are evaporated out from the flash evaporation tank; a rubber liquid produced at the bottom of the flash evaporation tank is sent in to the stripping tower through the pump, the isoprene residual in the rubber liquid is evaporated out by use of the solvent, the solvent is hydrocarbons with the content of less than 30mg/100g, and the distillation range is 60-80 DEG C. The stripping device and the stripping method can reduce methyl chloride decomposition, ensure that the isoprene content in the butyl rubber liquid for halogenation is lower than the required value of a halogenating reaction, and can ensure properties of the butyl rubber do not change by adopting optimum operating temperature and pressure.