Abstract: This article presented an implementation proposal, which could achieve and transfer the image files between mobile devices and PC based on Terrestrial Trunked Radio (TETRA) Digital Trunked Communication System. The key technologies and solutions of the image transmission, such as transmission protocol, large files transmission, packet loss, disorder packets' sequence and the completeness testing, were proposed. By packing the data connection configuration for mobile radio terminals, mobile equipment, as well as dispatching terminals, the image transmission feature based on digital trunked system was implemented, which expanded the business scope of the trunked system.