The invention discloses a method for purifying bromelin by a nano-titanium dioxide porous ceramic column chromatography, belonging to the technical field of enzyme separation and purification, mainly solving the problems of bromelin purification and enzymatic activity preservation. The technical scheme comprises the following steps of: manufacturing a porous ceramic column chromatography stuffing by a utilizing ceramic sintering technology; purifying the bromelin by adopting a column chromatography technology; and maximally preserving enzymatic activity through ultrafiltration and freeze-drying to obtain a finished product of the bromelin with the amount of activity units reaching 6 million. The invention is a high-efficiency and safe method for preparing the high-activity bromelin, and the product can be used as food or medicine raw material to be widely applied to the fields of food, biomedical industry and the like.