In the Jovian magnetosphere, an electric current system within the ‘current sheet’ generates a magnetic field, which is comparable to or dominating the Jovian intrinsic field in the nightside magnetosphere. However, update of an existing model of the magnetospheric field using newly acquired data by Galileo and Juno have never been conducted since it was first formulated in 1997. Here we used the data by Voyager 1/2, Galileo and Juno to revise the current sheet model as well as the magnetospheric field model based on each spacecraft data. We derived models that reproduced each data well, and revealed long-term variations of both current sheet and magnetospheric field over several decades. The updated models were found useful to detect dynamic events in the magnetosphere such as magnetopause deformation and plasmoid generation. They can also be used as external fields necessary for probing into the Galilean icy moons by electromagnetic induction methods.