Abstract: In the light of the existing poor dynamic balance performance of the forward-transfer rotary drum of the new type printing press produced by Beiren Goup, the study on its dynamic balance technique and the prediction of its structure modification are made. Some analysis and calculations are made on the defects of the drum such as large imbalance, taking long time and need great effort to make adjustment by hand so as to obtain the data about the drum's imbalance. According to the data the Modification scheme of the drum is made. Then through theoretical calculation it is proved that the imbalance has been greatly improved as compared with the original.