Radio wave propagation error is the main factor affecting positioning and timing accuracy of the enhanced loran system. Based on the analysis of loran-c positioning error, this paper proposes the basic principle and system composition of using differential loran to improve the local domain performance, discusses in detail the realization approach of differential correction generation, differential message transmission based on LDC, differential message design and user differential processing, and validates the differential loran technique system and performance improvement effect through experiments. It lays a technical foundation for the engineering? application? of? enhanced loran system.