The invention discloses a presswork encryption security printing technology based on multi-system quadrature amplitude modulation. By adopting the security printing technology, a paseudorandom modulating signal can be generated from anti-counterfeiting information through spread spectrum, encryption and channel coding, the anti-counterfeiting information can be embedded into a whole page through a multi-system quadrature amplitude modulation (QAM) mode, and the anti-counterfeiting information can be identified from any fragment in presswork identification. The invention has very strong smash-resistance, can effectively resist piracy behaviour based on cameras, scanners, electronic documents and the like, and can be widely applied to the field of presswork anti-counterfeit.