An improved corona generator structure includes a ground tube body sheathed within an insulating sleeve. One end of the ground tube body is provided with a sealing lid for being firmly coupled to the end portion of the ground tube body. At least one piece of high voltage electrode plate is coupled with the insulating sleeve. The high voltage electrode plate is provided with a plurality of spacers for allowing a gap of a substantially equal height to be formed between every area of the high voltage electrode plate and the insulating sleeve so as to uniformly distribute the corona on the high voltage electrode plate when electricity conducts therethrough. Furthermore, the two retaining sleeves are coupled to both end portions of the high voltage electrode plate and the insulating sleeve such that the high voltage electrode plate is firmly positioned on the insulating sleeve. By means of exposure of the high voltage electrode plate, a user can detach and wash the corona generator quickly and achieve efficacy of heat dissipation.