Abstract: Jacking prestressed concrete cylinder pipe (JPCCP) is increasingly widely used in large-section water diversion projects. The earth and water pressures around the pipe and the structural responses during construction are critical to ensuring project safety; however, in-situ measurements remain limited. Based on an ultra-large-diameter JPCCP project in China, full-scale field monitoring is conducted throughout entire the jacking process. Results indicate that the contact pressure around the pipe is essentially synchronized with the slurry pressure and could be classified into high-pressure and low-pressure phases corresponding to the grouting procedure. The effective earth pressure theory proves reliable in evaluating the pipe–soil–slurry contact states, with measurements indicating that the pipe remained in a persistent uplift state. Axial deformation of the pipe exhibits periodic fluctuations induced by the intermittent "jack-stoppage" cycle, and the hoop deformation is characterized by an asymmetric distribution-vertical compression and lateral tension. The middle and outer concrete layers maintain good deformation compatibility, even under complex working conditions. Compared with pipe conventional jacking, JPCCP structures must accommodate a complex interplay of jacking force transmission, non-uniform contact pressure, and interface shear coordination, which reflects the three-dimensional force mechanism of "pipe-soil-slurry-structure" quaternary coupling.