Having entered into the network printing times, we obtain great convenience and are confronted with many security problems. This paper focuses on the domain of network printer security which is still a blank field and proposes a whole security system for network printing which doesn't need to change the original architecture of network printers to solve the security problems of the existing network printers. The system adopts identity authentication technology to ensure the source data security, uses encryption technology to ensure data transmission security and utilizes embedded network firewall to enhance the anti-attack performance of network printers. The experimental results indicate that the whole security system for network printing can enhance the security of network printing and improve the ability against attacks of network printers effectively.