Method for preparing and purifying tertbutyl propionate

The invention relates to a method for preparing and purifying tertbutyl propionate. The method comprises the following steps of: continuously adding propionic acid and isobutylene-containing mixed gas raw materials into a catalyst filled esterifying tower according to the predefined proportion, controlling the predefined reaction pressure and temperature under the action of the catalyst, performing esterification reaction to obtain crude ester; delivering the obtained crude ester into a separating tower, leading propionic acid and isobutylene polymer and water to be azeotropic, controlling the gaseous phase reflux in the tower to be within the first temperature range, deacidifying and removing polymer of isobutylene, rectifying, collecting the rectification product between 115-125 DEG C, to obtain tertbutyl propionate. According to the method, the reaction is stable and safe, the purity of the product can achieve 99.5% or above, the sources of raw materials are sufficient, and the method is capable of realizi