Abstract: With the irradiation effects considered, the differential governing equations were improved for hydrogen diffusion, hydride precipitation and thermo-mechanical coupling behavior in zircaloy cladding tubes. Based on the corresponding equivalent integral weak forms for the multi-physics fields together with the developed coupling computational methods, the multi-field coupling finite element procedures were generated with the written files on FEPG platform, and they were verified. The effects of irradiation creep on the in-pile multi-field coupling behavior evolution in zircaloy cladding tubes were computed and analyzed. The results indicate that irradiation creep results in stress relaxation in the cladding tubes, which can significantly decrease the Von-Mises stresses, and simultaneous irradiation creep turns the negative hydrostatic stresses into positive ones. Compared with the results without considering irradiation creep, it can be found that irradiation creep will increase the absolute value of negative hydrostatic pressures and the outward hydrostatic stress gradients where the local mechanical interaction occurs between the fuel pellet and the cladding tube, leading to the decrease of hydrogen concentration there, and the increase of hydrogen concentration in the surrounding areas.