The invention discloses a medicine bottle cap pressing device convenient to adjust. The medicine bottle cap pressing device comprises a driving belt, a base, a fixing rod, a limiting disc, a cap pressing disc, an air cylinder, a plurality of lower pressing rods, a fixing disc and an output frame. The cap pressing plate, the limiting disc and the fixing disc are sequentially arranged on the outer side of the fixing rod from top to bottom, an air cylinder is arranged on the upper part of the cap pressing disc, a plurality of through holes are formed in the limiting disc, the lower pressing rodsare arranged on the bottom surface of the cap pressing disc. A plurality of fixing holes are formed in the fixing disc, the through holes, the lower pressing rods and the fixing holes are correspondedin position. A conveying belt and the output frame are arranged on two sides of the fixing disc respectively, the fixing disc is mounted on the base. The medicine bottle cap pressing device has the advantages that the cap pressing disc, the limiting disc and the fixing disc are arranged on the fixing rod sequentially, the lower pressing rods used for compressing are mounted at the bottom of the cap pressing disc, the descending height of the cap pressing disc for cap pressing is limited by the below limiting disc, and the limiting disc is adjusted through an adjusting thread to conveniently adjust the cap pressing height, so that repeated mounting is avoided, and cap pressing efficiency is improved.