The mechanistic interactions between EDDS with trace metals and major components in rhizospheric soil determine the bioavailability of metals in contaminated soils and subsequent phytoextraction application, which is not thoroughly understood. This study aims to investigate the macroscopic and molecular interactions of EDDS with Cu in the rhizosphere and the non-rhizosphere of Cu mine polluted agricultural soil. A multi-interlayer rhizobox planted with ryegrass was used to study the transport of EDDS and Cu from the non-rhizosphere to the rhizosphere. The results showed that EDDS (5 mM kg^-1) obviously dissociated Cu (by 285-690-fold), Fe (by 3.47-60.2-fold), and Al (by 2.43-5.31-fold) into the soluble fraction from soil composite compared to the control without EDDS. The combination of micro-X-ray fluorescence, X-ray absorption spectroscopy, and sequential extraction analysis revealed that EDDS primarily chelated with Cu from the adsorbed fraction with goethite instead of clay minerals; this phenomenon is probably due to the dissolution of Fe oxides promoted by EDDS. Moreover, as facilitated by ryegrass transpiration, EDDS and Cu were transported from the non-rhizosphere to the rhizosphere and accumulated in the latter. Cu was transported in the form of a CuEDDS complex with no competition from Fe and Al via solution modelling, due to a stronger complexation role of EDDS with Cu. The in situ mechanisms of Cu extraction and transport by EDDS in the rhizosphere are first elucidated with multiple speciation analysis methods, which are important in the application and improvement of EDDS-assisted phytoextraction in field-contaminated soils.